Mr Michael Portillo ended the guessing game yesterday and launched his effort to lead a thoughtful, understanding, moderate, internationalist and inclusive Conservative Party.
However Ms Ann Widdecombe made it clear that Mr Portillo's new inclusivity brand would probably not extend to her. The former Home Office minister signalled she would not serve in a shadow cabinet led by Mr Portillo, and that she might yet throw her weight behind Mr Kenneth Clarke.
"He is not going to ask me and I cannot, I simply cannot, serve Michael Portillo. It is as simple as that," she told BBC News 24. And in the absence yet of a deal on the vexed question of the euro - and how to handle it during any referendum - the former deputy prime minister, Mr Michael Heseltine, urged Mr Clarke not to abandon the field.
With another two weeks to the close of nominations for the vacancy declared by Mr William Hague, Mr Heseltine told the BBC: "I think it's too early to be certain about the who, it's about the how, the debate that's just beginning."
Mr Heseltine insisted that "a party that can't embrace Kenneth Clarke is not putting itself in a position to win". And he warned: "If the fault-line of Europe is allowed to persist then I don't see how you are going to unite the party."
Mr Portillo made his opening gambit with a promise to do that. Following two "catastrophic" election defeats, Mr Portillo said the Conservative Party required "huge changes" in its style and policy focus.
The Conservatives, he said, had to stop talking to themselves and "show that we are people like other people, and that their concerns are our concerns". In their "demeanour and tone", he said, they had to show themselves "thoughtful, understanding and moderate".
Pledging a shadow cabinet team bound by common purpose and collegiate spirit, Mr Portillo continued: "We must be a party able to appeal to the whole diversity of people who live in the United Kingdom, to both sexes, to all ages, and to those whose family origins are outside Britain."
Seeming to confirm his reported criticisms of the recent election campaign, Mr Portillo said his team would need to show its commitment to understanding the problems affecting health, education and transport, and to developing policies to improve them.
He also promised a less harsh approach to the role of leader of the opposition, saying: "I would wish to be moderate and thoughtful in the things that I say about the government and our other political opponents. The public is tired of yah-boo politics."
And on Europe, he said his Conservative Party - while still Eurosceptical - would adopt an "internationalist" approach in concert with other centre and centre-right parties in the EU.
"The majority of us think it would be wrong for Britain to enter the single currency," said Mr Portillo: "But our arguments would carry more weight if they're seen to come from a party which is internationalist and engaged in friendly debate with our neighbours." He said this would also "make life more comfortable" for members of the Conservative Party who took a contrary view on the euro.
It remained unclear last night precisely how comfortable a Portillo leadership could make life for Mr Clarke.
Speculation had been rife about a "dream ticket", which might see the former chancellor back Mr Portillo in return for freedom as a shadow cabinet member to campaign for a Yes vote in a euro referendum.
However, one well-placed Tory source yesterday suggested this was easier in theory than in practice, and said uncertainty about the precise timing of any referemdum was a complicating factor.
Mr Hesltine appeared to accept yesterday that Mr Clarke's destiny might be to play the role of king-maker in the leadership contest.
"My message is, don't abandon the field. Whether that means standing is for him to decide. There are many ways in which he can play an active role," he said.
But Ms Widdecombe suggested she might back Mr Clarke if he chose to stand. "I very much hope the next shadow cabinet includes Kenneth Clarke. He is a formidable, very significant man. If Kenneth Clarke decides to stand for leader I shall consider my position."