General Election 2015: Cameron points finger at Lib Dems over Sturgeon leaked memo row

Exclusive: An adviser to Alistair Carmichael, the Lib Dem Scottish Secretary, is expected to be questioned by Cabinet Office officials conducting a leak inquiry

Nicola Sturgeon is reported to have said she’d rather see “David Cameron remain as PM” (Getty)

David Cameron has pointed a finger of suspicion at the Liberal Democrats in the row over who leaked a memo alleging that Nicola Sturgeon wanted to see him remain prime minister.

An adviser to Alistair Carmichael, the Lib Dem Scottish Secretary, is expected to be questioned by Cabinet Office officials conducting a leak inquiry. But senior Lib Dems accuse the Tories of playing a “blame game” at their expense.

Ms Sturgeon, the SNP First Minister, complained of “dirty tricks” after a confidential memo written in the Scotland Office claimed she told Sylvie Bermann, the French Ambassador to the UK, that she did not see Ed Miliband as “prime ministerial material.” Ms Sturgeon, who has pledged to “lock out” the Conservatives after the election by working with other parties including Labour, has emphatically denied expressing a preference for Mr Cameron.

In an interview with The Independent, Mr Cameron said: “There is a leak inquiry underway. It is a proper one and I hope we get the answer because I do deplore leaks of this kind. You have to have private diplomatic space in which to talk. I hope we get to the bottom of who did it.”

Asked if he suspected the hand of the Lib Dems, Mr Cameron replied: “I have heard very clearly David Mundell [the Tory Scotland Office Minister] saying it wasn't him, so one does wonder.”

The Prime Minister’s suggestion will anger the Lib Dems at a time when relations between the Coalition partners are increasingly strained. In his interview, Mr Cameron branded Nick Clegg and other senior Lib Dems “a bit desperate” after they attacked the Conservatives in recent days.

An adviser to Alistair Carmichael, the Lib Dem Scottish Secretary, is expected to be questioned by Cabinet Office officials (Getty) (Getty Images)

The Prime Minister said: “The minor parties are going to make a lot of noise. They want to be heard and are worried about being left out of a fundamental choice of which team runs the country. I don’t think it works. They should run on their record, not on part of it. There is a lot to be proud of. I am running on the record – the difficult bits as well as the easy bits.”

However, Mr Cameron declined to entirely rule out forming another coalition with Mr Clegg’s party in order to keep Labour out. “I don’t want to, I am not aiming to. I am not going to speculate on anything other than victory,” he said.