Lord Ashcroft, who put £5m into marginal seats, is said to be furious with Cameron for doing TV debates and a lack of support over the 'non-dom' status row

David Cameron was facing a growing backlash from his own MPs and party grandees today over the conduct of an election campaign that left him short of an overall majority and trying to make a deal with the Lib Dems.

The Observer can reveal that Lord Ashcroft, who pumped £5m into marginal seats, is furious with the Tory leader for having agreed to take part in television debates that he believes undid much of his work for the party.

Friends of Ashcroft also say the peer is angry because he believes Cameron failed to stand up for him properly in the row over his "non-dom" tax status, which harmed the Tories in the run-up to the election.

Today, one senior frontbencher rounded on the Conservative leader, demanding that he sack key figures involved in the campaign, including the man who ran it, George Osborne, the shadow chancellor. The frontbencher said: "He ran his campaign from the back of his Jaguar with a smug, smarmy little clique – people like Osborne, [Oliver] Letwin and Michael Gove. He should get rid of all of them. The party will settle for nothing less."

Another senior and normally loyal Tory MP complained that Cameron's big idea for the campaign – "the Big Society", under which armies of volunteers would come together to tackle the country's ills – was "complete crap".

"We couldn't sell that stuff on the doorstep. It was pathetic. All we needed was a simple message on policy. We could have won a majority if we had not had to try to sell this nonsense."

Cameron is certain to feel the wrath of his MPs at an emergency meeting of the 1922 committee of backbenchers tomorrow, called to discuss a possible coalition with the Lib Dems.

Today, Tim Montgomerie, the editor of the ConservativeHome website, posted a blog saying that Cameron had to adopt a more collegiate style of leadership if he was to have any chance of taking the party with him in talks on a possible deal with the Lib Dems.

For months, leading Tories have complained that the election strategy was being drawn up by a narrow group around the party leader, including Osborne, Letwin, Gove, Steve Hilton, his close adviser, and his communications chief, Andy Coulson.

Arguably the most damaging for Cameron is the tension with Ashcroft. In the early hours of Friday morning, when a hung parliament had become inevitable, Ashcroft said the TV leaders' debates had been a turning point.

"I think from the time the Conservatives were ahead, we then had the debates, which has quite obviously turned everything topsy-turvy and what were natural assumptions before those debates changed the whole of the playing field," he said. "This is the type of result we are now seeing as a consequence of those debates."

Taking "a pure strategic hindsight view" he said there was a "balanced argument" over whether David Cameron should have taken part.A friend of Ashcroft told the Observer that the peer held Cameron personally responsible for the emergence of Clegg as a genuine rival: "He believes it knocked several points off our poll ratings and that, without it, we would have won."