Michael Howard acknowledged for the first time yesterday that the Conservatives might not win the next general election.
He refused to rule out the possibility when asked if he would stand down as party leader in the event of a defeat.
But Mr Howard insisted the Conservatives "can" win the election - as he made a speech outlining his tax-cutting agenda to mark the launch of the first part of the party's manifesto.
Asked on BBC Radio 4's Today programme whether he would stay on as leader in the event of a defeat, Mr Howard said: "If my party want me to do that and I think I can continue to make a contribution, then yes I will." Previously, Mr Howard has refused to acknowledge the possibility of defeat in the election, expected in May.
He said: "I am working very hard to win this election, there is no substitute for victory and it is victory I believe we can achieve, not for our sake, but for the sake of a country which needs to travel in a different direction."
The Conservatives revealed their pitch to what they call Britain's "forgotten majority" by publishing the preface to their election manifesto on Monday. The party has abandoned the traditional timetable for publishing its manifesto in favour of releasing it in chapters to maximise publicity in the run-up to the expected election date.
Labour attacked the document as "Thatcherism in instalments".
But yesterday Mr Howard said in a speech in Wellingborough, Northamptonshire: "My hope for Britain is ambitious but simple; to give the forgotten majority control over their own lives and the chance of a better future. Everyone should have the opportunity to live the British dream."
He claimed rising taxation and public-sector waste "threatens our economic prosperity" and promised smaller government to help people who work hard and save hard and had been "forgotten, neglected and taken for granted by Mr Blair".
He insisted that the Government should reduce Whitehall control. He said: "We need to give power back to the people. To the professionals, the doctors, nurses and teachers who know better how to care for the sick or teach children than ministers and bureaucrats in Whitehall. To the parents and patients who will make the right decisions if they are only given the chance.
"To the wage earners who deserve to keep more of the money they earn and know better how to spend it than politicians in Whitehall." Mr Howard declared: "I offer the British people decisive leadership, a clear path ahead and a vision of a country achieving its full potential. While others talk, we will act. In the coming weeks I will release the individual chapters of our manifesto for government. They will explain in detail exactly how and when we will deliver on our five priorities - lower taxes, cleaner hospitals, school discipline, controlled immigration and more police.
"No one will have to take us on trust - we have a Timetable for Action so that people can hold us to account.
"Everything a Conservative government does will be a means to one end - and that end is opportunity."
Alan Milburn, the Chancellor of the Duchy of Lancaster and Labour's election co- ordinator, said: "The first sentence of any Tory manifesto should be an apology to Britain's hard-working families for the Tory failed past of boom and bust, mortgage misery and cuts to schools, hospitals and the police."
Simon Hughes, the Liberal Democrat president, added: "The Conservatives lost the confidence of the British public in 1997 and they have not regained it. The Liberal Democrats are gaining the confidence of the electorate in larger numbers every year and we look forward to great progress in seats and votes whenever the Prime Minister names the date for the next election."
HOW THE MANIFESTOS COMPARE
Tony Blair and his election supremo, Alan Milburn, are focusing on Britain's "hard-working families". They promise an expansion of childcare places and extended school with breakfast and after-school clubs. Mr Blair has echoed the conservative rhetoric on choice in public services. He is expected to pledge not to raise income tax rates. Goes into the election on the back of legislation to introduce ID cards, set up a serious and organised crime agency and extend antisocial behaviour orders.
Michael Howard surprised his opponents on Monday by publishing the first part of his party's election manifesto. Detailed policy sections will follow. The Tories are pledging to champion Britain's "forgotten majority" with an end to tax rises and a campaign to shed bureaucracy from government by slicing departmental "waste". The party pledges greater choice in health and education, increases in police numbers and radical reform of the immigration system to impose quotas for people entering Britain.
Charles Kennedy was first off the blocks in October with a substantial "pre-manifesto" document under the slogan "Freedom, fairness, trust". The Liberal Democrats are promising to abolish council tax, axe university tuition fees and put 10,000 police officers on the beat, paid for by scrapping ID cards. The party plans to pay for many of its proposals with a new 50 per cent top rate of tax on incomes over £100,000 and proposes the abolition of the Department for Trade and Industry.