Michael Howard finally confirmed today that he is to stand for the leadership of the Conservative Party.
The shadow chancellor made the announcement after a succession of Conservative Party heavyweights said they would stand aside in his favour in a bid to ensure a one-horse race to succeed Iain Duncan Smith.
Mr Duncan Smith announced his resignation last night after losing a vote of confidence among Tory MPs.
Senior party figures, including David Davis and Oliver Letwin, have given their backing to the former home secretary.
Deputy Tory leader Michael Ancram has also pledged to support Mr Howard as long as he is the only candidate.
Mr Howard, speaking at London's Saatchi gallery, said: "This is a great party. We are its trustees. I will lead this party from the centre. We will offer a new kind of politics."
To cheers and applause from supporters, Mr Howard promised to lead the Tory Party "from its centre" and to include figures from all wings of the party in his team.
The Tories would be a party for "all Britain and all Britons" and would offer "a different kind of politics", he said.
Mr Howard said: "I am announcing today that I am a candidate for the leadership of the Conservative Party.
"I pay tribute first of all to Iain Duncan Smith, to his courage, to his dignity, to his decency. and to what he has achieved for us in the last two years.
"This is a great party, the longest-standing, most successful party in the history of democracy. There has been no other party that has done so much or achieved so much as ours. We are its trustees.
"At its best, we have a party broad and generous, broad in appeal and generous in outlook - a party capable of representing all Britain and all Britons.
"I will lead this party from its centre. I will call on the talents of all in the party and the party will expect all to answer that call."
Mr Howard said he would not be afraid to make the case for lower taxes. He added: "Not for us pledges that mortgage Britain's future."
He said the party had begun to form the policies to extend choice to everyone, not just those who could afford it.
The Conservatives would be internationalist under his leadership. If it raised concerns about the EU, it would not be because Tories were "little Englanders".
It was because they saw it as "too intrusive, too regimented" for the fast-flowing era of globalisation.
He said he was not born into the Tory Party but chose it because it offered Britain "its brightest future".
Mr Howard said the Tories must put "ancient feuds" in the past and "build afresh". The party was only "in the foothills" of its preparation for the upcoming general election and would need "stamina and comradeship" to succeed.
"Today once more, we are seizing our destiny," he told supporters. "Britain deserves better than it has today. It is our destiny to provide it.
"We must prove that we are equal to that challenge."
Mr Howard revealed that he would be speaking later today to former Chancellor Kenneth Clarke, who was tipped as a possible candidate in the leadership race but has not yet declared his intentions.
He said they would discuss "the best way in which we can work together for the future of our country and the future of our party".
Mr Howard said there was "no coup" to hand him the party leadership. He said he would be the new leader if there were no other candidates. But he said he wanted to give the wider party the chance to ratify his appointment.
"The rules do enable us to go to our membership in the party and ask them to ratify this choice," he said.
"That is something I would be keen and eager to do."
He said he had been intimately involved in drawing up the policies announced under Mr Duncan Smith's leadership.
"I claim part-authorship," he said.
"I think they are policies which are relevant to the everyday lives of the people of our country. They are policies which are going to make the everyday lives of the people of our country better."