With John Major today backing Kenneth Clarke to be the next Conservative Party leader, each candidate has received the backing of a key newspaper.

Yesterday, Clarke's campaign team launched a sustained assault to rebut Lady Thatcher's support for Iain Duncan Smith, with Lord Heseltine and Ann Widdecombe claiming that Thatcher should have kept her views private.

Clarke today received the backing of the Daily Mail. In a front page comment, the Mail called for the "insanity" over Europe to stop and argued that "the fact is the Tories must not make the mistake again of opting for an inexperienced unknown - a mistake they have already made twice before."

The paper says Clarke's "take me as you find me" sincerity would contrast with Tony Blair's spin-doctored image and points to his experience in the highest offices of state.

While praising Iain Duncan Smith for his "honesty, conviction and courage" the paper says there are "question marks over his charisma" and his ability to connect with ordinary voters.

However, Duncan Smith today receives support from the Times, which says Clarke is out of tune with his party on the euro and European federalism.

"[Clarke's] obsession with Europe and the divisions caused by his outlook would mean that, from the moment Mr Clarke became leader, his party would talk about little else," says the paper in a leading article.

The Times also says Clarke is "more tank than think" in his ability to develop new ideas but its endorsement of Duncan Smith is lukewarm, saying it is "hard to be hopeful and impossible to be certain" about his leadership potential.

The Sun announces that Dixons boss, Stanley Kalms, has lined up 12 leading businessmen to declare their support for Duncan Smith. The paper backs Duncan Smith and reassures Central Office that "There's hope" for the Conservatives, "people will vote Tory, one day".

As the fight for the Tory leadership hots up, Duncan Smith and Clarke face each other in a live debate on BBC 2's Newsnight.