NICOLA Sturgeon will not call a second independence referendum because the financial black hole facing Scotland would make the prospect of leaving the United Kingdom “utterly unrealistic,” Chris Grayling, the Commons Leader has insisted.

Speaking at a Westminster correspondents’ lunch, the Conservative frontbencher was asked if he thought the First Minister was just bluffing when she suggested the UK voting to leave the European Union while Scotland wanted to remain would probably lead to a second independence poll.

He replied: “They are making a noise but I don’t think they are actually really intending to try for a second referendum.”

Referring to the collapse in the oil price, Mr Grayling said: “If Scotland had voted for independence, it would now be in deep trouble financially. They had predicated their own future finances on an oil price in or around $100 a barrel; it’s now fallen down nearer $30 a barrel.

“They would have the most monumental financial black hole and the idea Scotland could now have, in whatever circumstances, a second referendum and vote for independence any time soon is just utterly financially unrealistic.”

The MP for Epsom said he believed this was the case in 2014 when the SNP had failed to answer the “big questions about Scotland’s future financial position”.

He went on: “But anyone in Scotland who is thinking about independence should take a step back, look at the oil price and look at the fact that Scotland today is still doing well, the economy is doing well, it’s doing well in employment terms; that is happening because it’s part of a strong UK economy and they wouldn’t get that, if they went for independence again.”

In response, the SNP’s Angus Brendan MacNeil pointed out how the latest opinion poll showed 54 per cent of Scots would support a second independence referendum if the UK voted to leave the EU but Scotland voted to stay. The snapshot also said 52 per cent of Scots would Yes in such circumstances.

He stressed that the Irish economy had no oil yet grew seven per cent this year and that the UK Government should not attempt to give anyone any lessons on economic management given it had run up its own economic black hole for the last 15 years.

“It’s a myth put about by Westminster that we need Westminster to be successful,” declared the Western Isles MP.

He added that he was confident there would be a second independence referendum whether it was just before or just after the 2020 general election. “The SNP will have to do it because it is what the people will want. They can’t put up with Tory cuts forever.”

Mr Grayling also talked up Tory prospects in May’s Scottish parliamentary election and suggested Labour was in danger of not winning a single constituency seat.

“I’m very optimistic. We have a good campaign and Ruth Davidson is doing a great job as leader…There is a real question-mark over whether Labour will win any constituencies at all in Scotland whereas I’m pretty confident we will win some constituencies in Scotland.”

He went on: “It’s clearly a battle between us and Labour to come second...If we overtake Labour, that would be an extraordinary blow for Labour; it’s a stretch but we are working towards it.

“What is interesting is Labour is in danger of not winning a single constituency and that would be a desperate reversal for them,” Mr Graylling added.

The well-known eurosceptic cabinet minister who is even tipped by some to lead the leave campaign, was asked if David Cameron would have to step down if he was on the losing side and replied: “I’m very clear about this; David Cameron remains the Prime Minister whatever the result is.”

Speaking under the watchful eye of Downing Street media chief Craig Oliver, he explained: “Firstly, he has a mandate for five years from the people of this country. Secondly, if we were to vote to leave, there is a big challenge to prepare for the ground to leave and negotiate the terms on which we would leave. The idea we would destabilise our government at that moment in time by trying to get through a leadership contest would be absolutely the wrong thing to do.

“So I’m very clear whatever the result of the European referendum, David Cameron must remain the Prime Minister.”

He praised the PM for deciding to allow individual ministers to campaign on either side once the renegotiation was over, saying this was "entirely fair and proper". But he refused to estimate how many of his colleagues would back the Leave campaign once they were free to do so.

He added that Mr Cameron's position was the "grown-up thing" to do and questioned whether or not other party leaders would grant their MPs similar freedom.