The big talking point is a taboo subject

Andrew Grice on the delegates' mood

(GETTY)

The Conservatives are not being triumphalist at their Birmingham conference but can't hide their pleasure at being back in power. Ruthlessly airbrushed out of the picture is their failure to win an overall majority against an unpopular prime minister and an exhausted Labour government, with a Rolls-Royce campaign against a Labour penny farthing.

"It's the great unmentionable," one Conservative adviser said. A Tory MP added: "It's 'don't mention the war' time; no one wants to recall that we didn't win it." Ask David Cameron's close allies about this and you get short shrift. "He is Prime Minister. That's all that matters," one snapped.

The election result is being discussed in the bars, at receptions and at some fringe meetings. Traditionalists grumble that Mr Cameron's timidity on issues such as immigration and welfare reform cost the party votes. The Cameroons, anxious to deflect criticism of the campaign, insist that a more right-wing one would have made matters worse.

"Too many people saw us as the same old Tories," one Cabinet minister said. Mr Cameron believes the party could not complete the detoxification of the Tory brand in opposition. "People don't believe us when we say we're not two-headed Thatcherite monsters, so we'll just have to prove that we're not," one ally said.

Lord Ashcroft, the outgoing deputy Tory chairman who conducted extensive post-election polling, argued: "It does not matter what your policies are if your brand is as tarnished as ours." He found that voters believe the Tories are "in it for themselves"; represent the rich not the poor; cannot be trusted and are still damaged by sleaze. He also highlighted mistakes in the Tory campaign: agreeing to three-way TV debates allowed Nick Clegg to grab the "change" mantle, there were too many negative attacks on Mr Brown and the party failed to get the its message across.

The Conservatives' internal post-mortem, which has not been published, cites a disappointing performance amongst ethnic minorities, public-sector workers and benefit claimants, and in Scotland, where the party won only one seat. Mr Cameron is being pressed to recruit staff at Tory HQ for a major push in the black and Asian community. But wooing public sector employees and benefit claimants will be difficult at a time when public jobs are being cut and the welfare budget squeezed.

There will be no formal debate about the election at the conference. The closest thing to it will come today when the ConservativeHome website devotes a fringe meeting to the subject. In a report to celebrate the Tories' return to power, ConservativeHome says Mr Cameron's key "big society" message "failed to cut through to most voters".

Of course, the Coalition with the Lib Dems offers Mr Cameron a unique opportunity to finally detoxify the Tory brand. No wonder Conservative ministers hug their Liberal Democrat counterparts so close.