Ken Clarke is "anguishing" over whether to stand for Conservative Party leader but is the best qualified person for the role, Michael Heseltine has said.
Mr Clarke is the best potential contender, Lord Heseltine says
The former deputy prime minister said the public found Mr Clarke approachable although winning an election would prove a "very difficult battle".
He welcomed a BBC poll suggesting most constituency chairmen in Tory-held seats want MPs to choose a new leader.
Party members currently vote for its leader from a shortlist chosen by MPs.
The party's Board is to meet on Monday to start discussing potential changes to the rules.
Sixty-six chairmen in the 197 Tory-held seats responded to the survey for BBC Radio 4's Today Programme, with 36 saying party members should not be able to choose.
Former shadow international development secretary John Bercow has also given Mr Clarke his backing, saying he was "the most impressive beast in the Tory jungle".
However, other reported proposals to changes the way the Conservative Party is run drew caution from former frontbencher Damian Green.
He said MPs and constituency associations may find themselves under greater central control, stifling constructive debate within the party.
The Tory membership were given the right to choose the leader under changes introduced by William Hague.
MPs have complained the move left them with too little influence over such a major decision.
David Davis was the most popular choice for leader when the question was posed in the survey last week.
However the small number of responses - only 26 chairmen chose to answer this question - made Mr Davis' popularity very unreliable, the survey suggested.
Many others had thought it was too early to choose a new leader.
Other contenders for the Tory leadership could include the shadow home secretary Mr Davis, shadow foreign secretary Liam Fox, shadow work and pensions secretary Sir Malcolm Rifkind and shadow education secretary David Cameron.
Lord Heseltine said the survey showed a "deeper movement than perhaps one might have suspected".
Twenty-six respondents said they wanted David Davis for leader
"I and many others have been calling for MPs to reassert control over this process. It seems to me... sanity is breaking out, the party wants to win, traditionally, historically that has always been a strong motivation," the Tory peer told Today.
He said the voluntary party activists were relatively elderly and seemed obsessed with Britain's relations with Europe, which is why the pro-integration Mr Clarke had been defeated in a previous leadership challenge in 2001.
He said such people were "not representative of the middle ground that we have got to regain if there's a chance of a Tory government".
If the decision to appoint a new leader had been left with MPs, the Tories would have chosen Mr Clarke ahead of Iain Duncan Smith, Lord Heseltine said.
Former chancellor Mr Clarke had been "extraordinarily badly treated by the Conservative Party", he added.
"Ken in the end is a politician with great ability and great ambition... I'm absolutely clear that he has not made up his mind, that he is anguishing."