The training college of the Police Service of Northern Ireland isn't used to the glare of publicity. Standing like a giant stage set behind an imposing green wall on Garnerville Road in east Belfast, it abuts the loyalist, flag-waving community of Knocknagoney housing estate: a decent place characterised by well-kept gardens and respectable, though partisan neighbours. This architecturally challenged former catering college has preferred to go quietly and discreetly about its business since recommendations from the Patten Report - the blueprint put forward by Chris Patten, the former Hong Kong governor and Conservative cabinet minister - decreed that the both lauded and criticised Royal Ulster Constabulary (RUC) should become the PSNI.

In November 2001, the police service was given a face-lift and a shot of Botox. A new name, badge and uniform were introduced in an attempt to promote a culture of tolerance and understanding between the Catholic and Protestant communities of Northern Ireland. The province has held its breath ever since.

The day I meet Mairead Smith, cloistered in a classroom of fellow students at the training college, a local newspaper reports that an alleged IRA front organisation, Community Restorative Justice, is in line to receive millions of pounds of taxpayers' cash to fund its own "police force". Critics of the group claim it has set itself up as an alternative law enforcement agency in 14 republican areas (the loyalists have an equivalent - Northern Ireland Alternatives).

Sitting with Smith, the irony is obvious. A Catholic from a nationalist area, the 25-year-old mother of two is in the middle of police training while some other nationalists are still refusing to accept the role of the PSNI in their community and, by extension, her role.

Crucially, all recruitment is done on a 50-50 religious basis in an attempt to address the historical religious imbalance in the police. But the fact remains that not everyone has accepted this multi-faceted change to policing and the 50-50 provides a dramatic backdrop to one of the most acrimonious discussions in the province. While the politics of Northern Ireland have become a ponderous game of cat and mouse, with both sides intoning almost the same psalm, one of the more vexing questions is how exactly you build a bridge between the state, the police and the people. Among the vast swaths of opinion, argument and conjecture over its future, the voices that are missing are those of the police recruits themselves.

It's early afternoon and Smith is all smiles, freckles and crisp uniform. Straight-backed with her hands clasped tightly, she peers through delicate metal frames. Another five recruits sit around, similarly straight-backed and with fiercely scrubbed boots in case anyone ridicules their polishing skills. The males have neatly shorn haircuts. The students are attentive, eager and filled with durable optimism. None of that is what you notice first, though. Glance through the window to the parade ground thick with marching, whiteshirted recruits and you witness the cuddly new, all-inclusive and non-discriminatory PSNI in action. Besides differing religions the recruits here come in all shapes and sizes; a few are euphemistically called "big lads" and it's easy to see why. Some of the females look more like dinner ladies than police trainees.

And, with their heavy Shetland-pony gait, they probably have been.

Minutes later the shouting, drilling and fixed gazes on arbitrary points ends and a noisy dispersal of recruits begins. The following day, amid a fanfare of pipes and cheers from nationalist and unionist families, there will be a graduation ceremony of 41 students, taking to 2003 the number who have graduated since the PSNI was formed.

Since November 2001, 17,488 Catholics have applied to join the PSNI, compared with 32,276 Protestants "and other". The latest recruitment campaign led to the highest level of interest yet, with nearly 7700 applicants competing for 220 places. Out of these, 37-per cent were Catholics. According to unionists, these figures demonstrate how the PSNI's 50-50 recruitment policy puts young Protestants who want to join the force at a marked disadvantage.

Packed with desks, course books - face downward to keep their place - and a whiteboard with illegible spidery handwriting, the class is typical of any college tutorial room.

Untypically, hanging from pegs on a wall are 16 PSNI caps that must be worn at all times outside the classroom. The students, slowly being transformed into creatures of routine, must also say "good morning", "good afternoon" or "good evening" whenever they pass someone by. Every student obeys orders as if they have anticipated them before they are given. This strict submission to hierarchy extends to the parade ground where, curiously, first thing every morning a handful of students are ordered to stand around a pot of jam with a knife sticking out of it. "To give students an appreciation of what it's like to stand for hours on end preserving a crime scene, " says Chief Inspector Mark Kernohan in a tone of grandfatherly admonishment when I inquire.

Earlier I met Kernohan, a portly man renowned for being rigorous with his recruits, and we agreed - lest he be accused of handpicking favourites - to choose a random group from a class of 16. Despite his reputation Kernohan, who has more than 20 years' service, frequently peppers his conversation with earnest anecdotes to remind the listener how successful PSNI policy is proving.

"I was asked to call the father of one recruit, a nationalist, who was unsure about turning up at the passing-out ceremony, " he says, flashing a smile. "He asked if there would be any Union flags flying. I said, 'No.' He asked if there would be anything with the Queen there. I said, 'No.'

He turned up the following day. Later, full of smiles, he said it was the best day he'd ever had." Kernohan grins widely, pleased by what amounts to a sermon.

None the less, of the 16 in the class two do not wish to be identified - either by name or by photograph. Whether the threat posed to them from publicity is real or imagined is anyone's guess, but they are excused. Of the six who make up the group, three male and three female, four are Catholic and two Protestant. Although they look very young, the average age of a recruit is currently 30. In 2001 it was 27.

Recruitment for the PSNI, adds Kernohan, is managed and delivered by Consensia, an independent partnership of professional firms.

A new cohort of recruits begins every five weeks. When Kernohan says he has no idea of the students' backgrounds, I joke that perhaps their names - Sean, Billy or Connor - might give their religion away. "Irish names have become very popular, " he murmurs, his tone slightly miffed. "Connor and Patrick . . ." (he searches for an answer) ". . . they've become quite common in the Protestant community."

When Mairead Smith, a Catholic from South Down, applied to the PSNI, she was following her older brother who joined two years ago. Having worked as a dental nurse she would not have considered the police even five years ago, given the legacy of sectarian problems. She joined up, she says, because she was eager to be part of the hopeful narrative in a changing country.

This despite the history of the province's stopstart peace process and pressure from some nationalists for young Catholics not to join.

Sinn Fein president Gerry Adams and the party leadership are still boycotting the new PSNI, claiming greater changes are needed. A number of republicans I speak with mockingly refer to the PSNI as "the Continuity RUC" in reference to the Continuity IRA - a shorthand way of saying no change has taken place. Last February there were news reports of dissident republicans intimidating nationalists wanting to join the PSNI by petrol bombing a house - believed to belong to a student policeman from the nationalist community.

"It wasn't in your face, " concedes Smith in a low, tight voice when I ask how the Troubles affected South Down. "My parents were fine about me joining when I did, but I don't think they would have been happy if it had been 10 years ago or even five." Her brother, she says, "ran about with mixed company where we grew up so it wasn't so bad. And I think he's been surprised by how it's worked out for him."

She only had one stipulation when applying:

that she wouldn't be stationed in her home town. "It wasn't to do with religion, more with me not wanting to be arresting acquaintances.

It's all a big change from my previous life, but I'm really loving it."

The hardest thing Smith has faced, ironically, is neither intimidation nor threats, but being away from her children - for the first four weeks, students stay in college accommodation.

She insists religion and gender are not issues in the way they might have been in the past. "I think today sex or gender doesn't really come into it, " she says, adding that in this part of the world, issues over religion happen no matter what line of work you are in.

The students remain civilians until they pass out and swear an oath, which has had previous references to the Queen removed. All PSNI students complete a 21-week course before undergoing a university-style assessment, for which they are allowed one resit. Those who fail the resit either resign from the course or are asked to leave. If they resign they can reapply immediately, but if asked to leave they must wait five years to reapply. Recruits are dispatched to police stations across Northern Ireland 10 weeks after passing out.

Whatever progress has been made, though, the seeds of tension still exist within the PSNI.

At a passing-out parade last November a Catholic recruit caused a furore by wearing an old IRA War of Independence medal. Unionists and police representatives expressed disbelief that the officer was allowed to have a Black and Tan medal, commemorating IRA members who fought British soldiers in the 1917-21 campaign. Not surprisingly, nationalists insisted he was entitled to do so. The PSNI, meanwhile, said officers whose relatives had been honoured by the British government or any other government are allowed to wear their medals at a graduation ceremony.

The Independent Commission on Policing in Northern Ireland was set up as part of the Good Friday Agreement with the task of providing "a new beginning to policing". In its report published in 1999, commonly referred to as the Patten Report, the commission made 175 recommendations, among them proposals regarding the composition, size and structure of the police service. It also recommended the creation of new accountability structures. In November 2001 the RUC became the PSNI.

The objective was to "depoliticise" policing.

According to the 16th report by the Police Oversight Commissioner, published on June 6, three-quarters of the Patten recommendations have been fully implemented.

Depending on what side of the barbed-wire fence you sit on, the RUC was either a paragon of policing decency or an organisation that became very good at being frightening.

Unionists saw the RUC as their force - the thin green line against terrorism, particularly the IRA. Nationalists and republicans viewed it as a bludgeon with which ordinary Catholic people were frequently battered. Whatever the perception, the RUC was commonly viewed as being bound up in the dispute about the state itself. By 1969 only 11-per cent of the RUC's 3500 recruits were Catholic. The RUC was disarmed and a new rank structure introduced.

The disarming was shortlived.

By 1971, sidearms were issued again as the campaign against police intensified. Manpower was gradually increased to 8500 for the RUC, though the proportion of Catholics in the force was about 8-per cent. While the RUC suffered heavily during the Troubles - 302 RUC and RUC Reserve officers have been killed as a result of the security situation since 1969 - tensions between the RUC and the nationalist community continued to mount, leading to the Patten Report's proposals. So far no members of the PSNI have been killed, but there are currently 639 officers on long-term sick leave - defined as an absence of more than 28 days.

In just a few years Northern Ireland has been dealt a full house of political and social experiments aimed at policing two communities at loggerheads. Even so, the prevailing perception is that there are actually three religions in Northern Ireland - Catholic, Protestant and Policeman. Suspicion remains on both sides.

Previously I arranged to meet one serving Catholic officer who had passed out more than two years earlier. A Protestant policeman whom he knew suggested he should apply.

When he approached another member of the PSNI to chat informally about joining, though, he was told he met nearly all the criteria but might not get in "because of the 50-50". He was told, "They're letting all the Taigs [Catholics] in." The recruiter mistakenly believed the applicant was a Protestant.

When I suggest to student officer Joe Kane, a 25-year-old Catholic and former postman, that there have been reports of nationalists being intimidated into not joining the PSNI, he replies diplomatically. "When I was joining there was a wee bit of me worrying about what people were thinking, " he says. "Where I live at the minute a load of people found out and I was a bit nervous, but they were supportive.

All the feedback was, 'fair play to you, wee man, I hope you do well'." Kane, with the face of a young pugilist, rubs his chin with one hand. His family comes from both sides of the community. "My friends joke that I'm a different person now."

Figures released in July show one in five regular officers in Northern Ireland are now Catholic. The government has set a target of 30-per cent Catholics by 2010-11. Sinn Fein's policing spokesman, Gerry Kelly, says of the recent statistic that it was a "sleight of hand" which has been used before. "Patten wanted the composition of policing as a whole to change, not just PSNI regular officers, " he says. "In terms of Patten, this statistic represents a change of only 1-per cent per year. If powers for policing and justice were transferred [to a restored Northern Ireland Assembly], persuading young nationalists and republicans to participate in a new beginning to policing would be much easier."

The Democratic Unionist Party (DUP) says it still has concerns. The 50-50 has long been criticised as unfair by some unionist politicians, including the DUP which has been calling for an end to what it brands "outrageous discrimination". Last year, in a tone of high umbrage, MEP Jim Allister raised the issue at the European Parliament human rights debate, claiming "exceptionally qualified young Protestants" were being refused admission because there was not a matching number of Catholics.

He urged the EU to ban religious discrimination in employment. In March, the unionist peer Lord Laird, in the House of Lords, argued that the quota system for levelling up the proportion of Catholics in the PSNI violates European anti-discrimination laws.

Kelly Gardiner has a slim face, asymmetrically upswept red hair and a confident, articulate voice that echoes around the classroom. A 26year-old Protestant from Ballymena, she remains unfazed by the criticisms of the PSNI from both sides of her community. The past 11 weeks, however, have been something of a culture shock. "It's a life-changing thing for most of us compared to what your life was like before, " she says. "There's nothing I can really identify with the way my life was like. To be in such a disciplined organisation - every minute of your day is accounted for.

"I live in the country and all my neighbours would be Protestants, but I don't think I've ever had a Protestant boyfriend. The majority of my friends are Catholics. It could have been quite easy for me to come up with a very narrow-minded attitude. I come from a town that's quite bad for its politics but it's how open-minded you are." For Gardiner, the truth of the matter is fairly prosaic. "People start to see the police now as a career as opposed to what they used to see it as . . ."

A few days earlier I talked with a Catholic policewoman working in Belfast who preferred to remain anonymous. "You join up and you get closer and closer to the horns of the bull, " she told me. "It's a dangerous occupation, but we need the police here. Both sides of the community do."

One former Catholic recruit from a staunch REAL LIVES republican area of Northern Ireland describes how he left the PSNI college after a few weeks' training more than a year ago. "The timing wasn't right, " he says. "Well, it was for me, but it wasn't for them." The "them" in question were members of the IRA and, whether through informal negotiation or intimidation, they made it clear their "problem" should vanish. He quit the course.

Although the police do not have exact figures for those leaving following intimidation from within their community, Kernohan insists he "could count on the fingers of one hand the amount of student officers that have had to leave because that community they have lived in are not ready to have a police officer in that street." Moreover, he insists that policy of intimidation seems now to be "leave people alone". There are others who leave simply because "a lot of them think they signed up for The Bill. It's not what they thought." A PSNI spokeswoman says she does not have the figure "at hand" of how many recruits have left the PSNI following passing out, nor how many are Catholics. "But we believe it to be low, " she adds.

If there is nervous unanimity over any subject it is firearms training, which begins once recruits have graduated. All officers in PSNI must complete firearms training and if an officer fails they must repeat it within one to three weeks. "Very scary, " says Donal Gorman, a trainee and former call-centre worker living in Bangor. "It is pressure. I can understand the reasons why, like, but I'm not looking forward to it."

Gorman, a Catholic and originally from the Republic of Ireland, drums his fingers on a table. A quiet 36-year-old with a nice line in irony, he prefers to keep what he does to himself. "I'm pretty new to Northern Ireland, " he says. "I don't tell." Although the PSNI cannot comment on the personal security of their officers, at the beginning of their training they are believed to be offered the use of a device to warn them if their cars have been booby-trapped.

"I've lived in Bangor for four years and I get on well with people, like, but it is a predominantly Protestant area and people would identify me straight away with being Catholic, so I'd be a little concerned. I've no issues, but I'm just a wee bit nervous about neighbours who you wouldn't know that well."

Lynsey Pyne, perhaps the quietest in the group, is looking forward to working in the community. A Protestant from outside Belfast, she was a student in Scotland until she was accepted at her second attempt. "When we first started, " she says, "I thought, 'I can't wait, ' but now we're halfway through [the course] I'm getting a bit nervous. My priorities have definitely changed. I'm definitely aware of who I am now." The group go back and forth, using words like trust, open, inclusion, accountable and transparency. After only 11 weeks they speak in terms of civilian life and life in the force. Then and now.

"I think a lot of people just think it's not a career they'd like to go into because of the trouble there was, " says Chris Patterson, a loquacious recruit with a more serious tone than the others. "Especially the targeting of Catholic officers from the IRA, people [Catholics] are maybe thinking it's just not worth that hassle." While Patterson does not at first strike you as a police recruit - he's a chartered accountant from Cushendun, a small village in County Antrim - his enthusiasm for his new career is evident. "In the Glens of Antrim my memories of the Troubles there, as they were called, would be relatively untouched. The police were relatively approachable and there wasn't a great deal of animosity between the police and the community. But I don't go round publicising I'm a student police officer. And I wouldn't be naive enough to think people wouldn't change their opinion of me

but, as a whole, I think we're well accepted." While he won't give specifics, there have been comments made to him about his religion, "but on the whole it's fine. Nothing I can't handle." We go outside for photographs.

The chairs are being prepared for the following day's passing-out ceremony. There is a large PSNI crescent on a board erected in the yard. Piped music blares over the Tannoy.

Two female police recruits jog slowly past.

Later, as we hand in our security passes, one guard at the gate laments the demise of the RUC pipe band. The "old guard", he says, meaning the RUC, "weren't happy". He shrugs. "Changed days." He says it with the stubbornness of an only child. "Definitely changed days." In the past, when the recruits were passing out there would be an army presence outside. Helicopters and armoured Land Rovers. Security is much more lax now.

A sign of progress, I say. He shrugs again.

A taxi pulls up to take us away. The young driver, clearly a nationalist, is intrigued and asks loads of questions. There's a boy on a small motorbike riding in the middle of the road. The driver says we should arrest him, then laughs. I say I'm a journalist. "Dead on, " he says. "I've never known one policeman to come out of that place yet. You're not a policeman and I'm not a taxi driver." He laughs again and I'm laughing with him. The suspicion remains.

For the politicians, separated by the stigma of mutual bitterness, the changes are too quick.

For others, like the six student recruits, as yet unravaged by opprobrium, they can't come quickly enough.