Katy Loudon's challenge is probably not one many people would envy.

The 43-year-old former primary school teacher has been selected as the SNP candidate in the Rutherglen and Hamilton West by-election at a time when her party is going through its biggest crisis in 50 years - and that's in the words of the party's president Michael Russell.

While support for independence remains steady with close to half of Scots backing Yes, according to a series of polls, support for the SNP has fallen while for Labour it is rising.

The latest research by YouGov last month found in terms of Westminster voting intention, the SNP now lead Labour by just four points, at 36% versus 32%.

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Katy Loudon, pictured in the SNP's hub for the Rutherglen and Hamilton West by-election. Photo Colin Mearns/The Herald.

This represents the lowest SNP vote share since 2018, while for Labour it is their best result since the 2014 independence referendum.

History books will no doubt be written in future on what lay behind the change in the SNP fortunes but at the moment a host of factors appear to have contributed to the party troubles - the long running police investigation into the finances, a bitter leadership contest and ongoing internal divisions.

Ms Loudon also has the disadvantage of being the SNP candidate after the party's last MP for the area MP Margaret Ferrier was ousted by local voters in Scotland's first recall petition after breaking lockdown rules. Ms Ferrier was elected as the SNP MP in 2015 and 2019, though sat as an independent once her Covid rules breach emerged in September 2020.

READ MORE: Humza Yousaf names his preferred date for Rutherglen by-election

Into the drama has stepped Ms Loudon, an SNP councillor in South Lanarkshire for six years and a woman fighting against the political tide. She's certainly not a fair-weather candidate and it's hard not to admire her grittiness and determination.

Eight of her party's MPs have announced their decisions to stand down from their Westminster seats at the general election expected next year.

Among them are several who have reached an age when they want to move away from frontline elected politics but others - including the party's deputy leader in the Commons Mhairi Black who is only 28 - have spoken out about the difficulties of life as an MP and cited difficulties in balancing work and family commitments for their decisions to move on.

I ask Councillor Loudon if such comments had not put her off as we meet in her election hub in the centre of Rutherglen at the end of a busy day when she's been knocking on doors and speaking to voters.

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"I think it is difficult to balance work and family life as a working parent. Full stop. Certainly, when I was first standing for election we always had support from the branch and support in the community like parent councils," she says.

"I've always said if you want me to be at something, there may be times when I have to bring my children along with me." She goes on to explain how she got the idea for doing so when she was studying for a Masters degree and went along to an SNP students' event where the Scottish Government Cabinet Secretary Angela Constance was attending with Ms Constance bringing her young son along too because of childcare issues.

The Herald: Stephen Flynn and Katy Loudon

Katy Loudon, the SNP candidate in the Ruthlerglen and Hamilton West by-election, with the party's Westminster leader Stephen Flynn.  Photo Colin Mearns/The Herald.

"That is the reality of working life for many people."

So will she be taking her two high school aged children may to Westminster occasionally?

"I'm sure if they get a long weekend in London they would be very happy," she replies.

Westminster returns from its summer recess this week with a date expected to be confirmed for the Rutherglen and Hamilton by-election tomorrow or Tuesday. First Minister Humza Yousaf said yesterday his preferred date October 5, the day Scottish Labour also prefer.

The Herald: Humza Yousaf and Katy Loudon at the SNP's by-election campaign launch

First Minister Humza Yousaf pictured with Katy Loudon at the launch of the SNP's campaign.  Colin Mearns/The Herald.

The polling day confirmation is expected to see all the parties ramp up their campaigns as the race enters its final month with Loudon and her team hoping to speak either face-to-face or by phone with all 80,000 voters in the constituency.

With Labour said to be the favourites to win, does she feel like the underdog?

"By-elections can be quite strange beasts because you have a mix of local issues and national issues at play," she says side stepping the question.

"Of course it's been a challenging few months but this is a by-election for this seat and that's what I am committed to fighting on because I want to represent this area."

A few weeks ago I posted on X (formerly Twitter) some photographs from the SNP and Labour launches which appeared to show differing styles the two parties were taking to their by-election campaigns.

Labour candidate Michael Shanks was pictured holding forth with reporters, while Ms Loudon appeared to be sitting behind First Minister Humza Yousaf while the FM did the talking.

READ MORE: Scottish Greens to stand in Rutherglen and Hamilton West by-election

From my point of view it was a contrast that struck me and which also seemed to represent the apparent reversal of fortunes for the two parties. Some in the SNP thought the comparison unfair. As a way of alluding to the matter, I ask Ms Loudon whether she believes her profile has been raised as the campaign developed.

"I've got to admit I was a little irked by some of those comments. If the First Minister is there, journalists are going to ask direct questions to him as they have the opportunity to do so," she says pointing out the episode was picked up by Labour deputy leader Jackie Baillie and a torrent of abuse and misogyny, she adds, became directed at her.

"I had comments about whether or not I was wearing lipstick, whether or not I was standing behind a man, whether or not I am shorter....I do think there was an element of misogyny - not in the reporting - but in what came after."

It's perhaps a moment that illustrates how intense and fractious the campaign between the SNP and Labour has been.

For their part the SNP have honed in on Labour "flip flopping" on policies such as the Conservatives' two child benefit cap to argue that there's not much that separates the two. (Labour did oppose the two child benefit cap and have now shifted position with Keir Starmer saying a Labour government would keep the controversial cap.)

Labour in turn have been capitalising on the police probe into the SNP as well as the former MP's Covid breach. Last week party deputy leader Jackie Baillie stepped up the attacks accusing the SNP of being "the most scandal-struck party in Scottish political history”.

Dame Jackie said: “The time has come for Katy Loudon to come clean and explain to the people of the area why a party that can’t run itself can be trusted to govern Rutherglen and Hamilton West.”

However the attack backfired, as allegations then emerged of a “poisonous” culture in the Labour group running South Lanarkshire Council.

Ms Loudon also points to the suspension of the council's Labour leader Joe Fagan since June for leaking confidential information. He insisted at the time his "conscience is clear".

She believes she has an advantage over the Labour candidate and others as she has represented part of the area as a councillor since 2017 and already has a public profile locally.

She says both local and national issues are coming up on the doorstep, most of all the cost of living crisis which she says is increasingly a concern among voters as colder weather approaches and people start to worry over their energy bills.

She argues that Scottish Government policies such as the Scottish Child Payment which have helped to alleviate financial troubles for Scots on lower with families and says she is proud of standing on the SNP's record in government.

But she does concede the police investigation into SNP finances has been brought up on the doorsteps.

"I've had a few people saying I know I am voting for the SNP but this is all going on," she says referring to the probe.

"I am not going to say it has not been a difficult few months. Of course it has been a difficult few months."

I ask if people have expressed disappointment with the party. "It's been more sadness than disappointment I think," she says.

Returning to one of my first questions, I press her if she was confident she can win the seat.

She says: "Yes I am, I wouldn't be standing if I didn't think I was the best person for the job."