DAVID Cameron has denied trying to sabotage the TV leaders' debates, insisting that he wanted to "unblock the log-jam" the broadcasters had created.

After the Prime Minister rejected the proposal for a head to head with Ed Miliband on April 30, a week before the May 7 election, Labour made clear its leader would be prepared to subject himself to a solo grilling by presenter Jeremy Paxman and a studio audience.

But Nick Clegg intervened to say he would take the Tory leader's place and spare the nation a "Miliband monologue".

The Liberal Democrat leader accused Conservative high command of "behaving as if they're ordering a drink in the drawing room of Downton Abbey".

He insisted: "It's not for the Conservatives to start telling people how these debates are going to happen; they belong to the British people. If David Cameron is too important or too busy to bother to actually defend the record of this government in a debate with Ed Miliband then, yeah, I'll offer up myself to do it instead."

The Labour leader, who during Prime Minister's Questions on Wednesday had challenged the PM to a head to head, was scathing about Mr Cameron's withdrawal from the option, accusing him of "cowering from the public".

"The British people deserve this debate," declared Mr Miliband. "I'll debate him any time, any place, anywhere. He should stop ducking and weaving and name the date."

Nicola Sturgeon, the SNP leader, was equally combative, branding the PM "feart".

The First Minister said: "David Cameron is clearly running scared of having to answer for his Government's record of failure and incompetence and this arrogance in trying to lay down the law is all about getting out of debates, not taking part."

She added: "I will debate him any time, anywhere, on any number of occasions. However, we have accepted the broadcasters' proposals and believe we should stick with that rather than allow a Tory Prime Minister to dictate the terms of debate."

There was also criticism from Ukip's Nigel Farage, who claimed Mr Cameron was trying to "sabotage" the debates, while the Electoral Reform Society said it would be a "national embarrassment" if the debates did not go ahead.

The most recent offer from the broadcasters of two debates involving seven party leaders and one between the PM and Leader of the Opposition was rejected by the Tory leader, who had previously expressed concerns about having any debates during the short campaign, fearing they would dominate the election. Instead, No 10 said his final offer was a one-off seven leaders' debate before March 30 when the UK Parliament is due to be dissolved.

Speaking during a visit to Staffordshire, Mr Cameron insisted he had been "completely consistent" on the debates, saying: "I haven't put hurdles in the way. The broadcasters came up with a series of proposals that other people realised were flawed.

"I am unblocking the log-jam and saying let's have this seven-cornered debate and get on with it before the campaign. Then, we can actually do what needs to be done, which is to get round the country during the election campaign."

He rejected claims that staging the debates before party manifestos were published would limit the opportunity to scrutinise their plans.

"Everyone knows what the Conservative proposals are and the Labour proposals are and the other parties can speak for themselves," added the PM.