The Guardian claims Michael Howard believes his decision to back away from a big push on immigration in the final days of the election campaign may have cost the Conservatives at least 10 extra seats in parliament.

The outgoing Tory leader is said to feel that he could have finished off Tony Blair because a further 10 Tory MPs would have cut Labour's majority to below 50, dealing a fatal blow to the prime minister.

Howard abandoned plans to return to the asylum issue in the final days because he wanted to present an upbeat message of what he would do as prime minister.

Meanwhile shadow environment secretary Tim Yeo has announced he is standing down from the frontbench so he can play an unhindered role in discussing the party's future.

Yeo is thought to be one of the Tories' leading modernisers and keen to see off a right-wing leadership. 

Nicholas Soames is also set to step down from the shadow Cabinet.

The shadow defence secretary is said to be keen to take a prominent role on the backbench 1922 committee.

Senior party figures have been offering their respective visions for the Tories following their third successive defeat.

David Willetts, the shadow work and pensions secretary, said: "I think the problem is we have never had a serious analysis about what the problem is," he said.

Sir Malcolm Rifkind, the former foreign secretary who has returned to parliament after an eight-year absence, made clear he still has ambitions when he confronted one of his main weaknesses - that at the age of 58 he is seen as too old.

"I think you can give as many examples of people in their 30s or people in their 60s or even in their 70s who have been great political leaders," he told GMTV.

And in a speech to the right of centre Politeia think tank tomorrow, the party's co-chairman Liam Fox, will set out his vision for a low tax economy with a greater role for the private sector in public services.

The Times claims Conservative members are already resisting moves to remove their say in choosing a leader.