One of the candidates battling to become the next Prime Minister argued that Scotland was “heavily subsidised by the English”.

Energy minister Andrea Leadsom also railed against the “enormously costly layers of government” created by Scottish devolution.

The subsidy claims came in a 2007 blog criticising the SNP Government's decision to abolish university tuition fees for Scottish students.

Mrs Leadsom emerged earlier this week the surprise challenger in the fight for the Tory leadership, knocked Michael Gove out of the race exactly a week after he appeared to do the same to Boris Johnson.

Read more: Boris Johnson backs Andrea Leadsom for Conservative leader

The pro-Leave campaigner now faces a run-off with the Home Secretary Theresa May, who called for the UK to stay in the EU.

Around 150,000 Conservative party members will now hand one of them the keys to No 10 on September 9.

The SNP claimed that the comments showed that Mrs Leadsom was “itching” to cut Scotland’s funding.

SNP MSP Michael Russell, the convenor of the Scottish Parliament’s Finance Committee, said: “We know that elements of the Tory party have for years been itching for the opportunity to hammer Scotland’s budget even further – and Ms Leadsom is just the latest senior Tory to raise questions over Scotland’s funding in recent weeks, following hot on the heels of Michael Gove and several others.

Read more: Tory leadership contest: Andrea Leadsom vows to 'banish the pessimists' as supporters march on Parliament

“It’s imperative that both leadership candidates now make it absolutely clear that they respect the fiscal framework signed up to by both the Scottish and UK Governments just a few months ago – and if they fail to do so, people in Scotland will be under no illusions as to what they have in store for our budget."

He also said that when the choice for the next Prime Minister is between Mrs Leadsom and Mrs May it was clear that whoever wins "Scotland will lose.”

Meanwhile, a Tory peer added his voice to calls for a shorter leadership contest.

Lord Cormack described Mr Cameron as a "lame duck" Prime Minister and said that he should be replaced before September.

Former party chairman Grant Shapps is among dozens of Tory MPs also calling for a swifter process.

But some have suggested that the move could unfairly favour the higher-profile Mrs May.

She picked up another high-powered backer yesterday (FRI).

The Defence Secretary Michael Fallon said that she was the candidate who could keep Britain safe.

Read more: The Midge: Tory hopeful Leadsom is it Maggie, Maggie, Maggie, back, back, back?

He said: "I think at this point she has the experience, the track record, to take this country forward now, to stabilise the economy."

In the wake of the shock Brexit vote the Home Secretary has insisted she can unite the party.

But her call to stay in the EU was rejected by most of the party’s members.

Scottish Tory leader Ruth Davidson has said that she backs Mrs May, but called on her to guarantee that all EU nationals currently living in the UK would be able to stay.

Mr Johnson also put pressure on the Home Secretary to make the same commitment.

Mrs Leadsom has said that she would allow all those currently living here to remain.

But her opponent accused her of inexperience, saying the pledge would include foreign criminals.

Mr Johnson said: "I think Andrea Leadsom would do a great job because she understands the positive advantages of leaving the EU and how you can turn that to a great opportunity for our country.

"There's one very important thing I think that both candidates have got to make clear - that is that EU nationals living here now have absolutely no problem and they are welcome, they are a vital part of our economy.

"Andrea has made that clear I think but I think that Theresa should make that clear as well."