Sir Malcolm Rifkind has staked his claim to the Conservative leadership with a rousing conference speech.
Speaking without notes, Sir Malcolm launched stinging attacks on Tony Blair and Gordon Brown and branded the Labour frontbench "political pygmies".
He said the Conservatives could only win the next election if they were based on the centre ground of politics.
Sir Malcolm was the first of the five declared candidates to succeed Michael Howard to make their 20 minute pitch.
A 50 to 1 outsider with the bookmakers before the speech, he admitted he had a "mountain to climb" to win the leadership.
Also at conference on Monday:
- Party chairman Francis Maude warned the Conservatives had to change, saying they "had no God-given right to survive".
- Family spokeswoman Theresa May, who has yet to say whether or not she will contest the leadership, said the Conservatives must "ditch yah-boo opportunism".
- Europhile ex-chancellor Kenneth Clarke described as a "paranoid fear" the thought that he might take the UK into the euro if he became Conservative leader and then prime minister.
- Shadow foreign secretary Liam Fox underlined his eurosceptic credentials by saying Conservatives should not be frightened to advocate withdrawing from the EU if the price of membership became too high.
- Shadow health spokesman Andrew Lansley ruled out standing in the leadership election because of a lack of support.
Sir Malcolm received an enthusiastic reaction from the representatives in the Winter Gardens as he attacked the "insufferable arrogance" of Gordon Brown and said Tony Blair was "like Bill Clinton without the sex", praising his skills as a politician but mocking his lack of principles.
He said Mr Blair could "convince most people of most things and himself of almost anything".
CV: Sir Malcolm Rifkind, 59, shadow work and pensions secretary
Key Quote: "We need to win back the millions of people who do not think of themselves as Conservatives but who voted for us in the past."
Best joke: "He is Bill Clinton without the sex.... so far as we know" (about Tony Blair)
Ovations: Eight rounds of applause - finale wins 56 seconds
Speech length: 17 minutes, 10 seconds
Name drops: Many Churchills, no Thatchers
Nick Assinder's verdict: Can still wow Tory activist with One Nation vision
But he warned the party not to be lulled into believing Mr Brown would take Labour to the left when he takes over from Mr Blair.
He warned Mr Brown was a "very big beast" who had already signalled his intention to fight in the centre - and would be a formidable opponent at the next election.
But he added: "Tony Blair, Gordon Brown yeah they're big beasts. But, you know, the rest of them, the rest of them, Jack Straw, John Prescott, David Blunkett, they're political pygmies.
"They think of themselves as model ministers. Well you know, in one sense, they're quite right. Because after all, what are models, but small imitations of the real thing?"
But he said the party did not have to be a "pale imitation of Labour" - it had its own moderate centre ground tradition in One Nation conservatism, pioneered by Winston Churchill.
He called for a return to these One Nation roots, which made the Conservatives a "unique combination of principle and patriotism".
He said the party had to be a "pragmatic, sensitive and moderate" one, which stood for "generosity of spirit and equality of opportunity".
Fellow candidates David Cameron and Kenneth Clarke will speak on Tuesday, with David Davis and the firth confirmed candidate, Liam Fox, addressing the conference on Wednesday.
A YouGov poll for the Daily Telegraph suggests that among Conservative voters it is a straight battle between Kenneth Clarke and David Davis.
They are tied with 30 per cent support, followed by David Cameron on 16 per cent, Liam Fox on 13 per cent, and Sir Malcolm Rifkind on 4 per cent.