Analysis: That was the easy part - now the hard work gets under way

Now the hard work begins, and David Cameron knows it. He may have clocked up 7,000 miles in six weeks during the Tory leadership contest, but his path to victory was remarkably smooth. Winning the country will be much harder. "It is a nightmare job, I know," Mr Cameron said in a rare unguarded moment.

Yesterday, in his victory speech, the new Tory leader acknowledged: "We have a vast mountain to climb." He must scale his first peak quickly: at noon today, when he enters the Commons chamber for Prime Minister's Questions. It will also be a litmus test for his promise to end what he called the "Punch and Judy" politics of Westminster. The obvious line of attack if Michael Howard were still Tory leader would be Tony Blair's climbdown over linking any cuts in Britain's rebate on its payments to the European Union to reform of the Common Agricultural Policy. Although the retreat offers Mr Cameron an open goal, some advisers are urging him to resist the temptation, and he may well do so.

Speaking about Europe would run counter to his drive to ensure the Tories map out a new agenda on issues such as climate change, the work-life balance, and poverty in Britain and the world, while turning their back on old agendas such as immigration and asylum, law and order and Europe.

There will be little respite for the new Tory leader after Prime Minister's Questions. Over the next two days, he will perform a tricky juggling act as he forms his Shadow Cabinet. He will have to balance the need to bring in fresh, young faces with the need for older, wiser heads to compensate for his own lack of experience. Mr Cameron knows he will have to make an impact on the public quickly, as first opinions about party leaders often stick - as do early mistakes, such as William Hague's baseball cap.

Cameron aides dismiss as "junk" the press speculation that he has a "100-day plan." He will take his time on policy, and may not finalise his new programme for two years. In the meantime, he hopes to convince the voters the Tories have changed simply by talking about the issues that matter to ordinary people, rather than what matters to the Tories.

Precisely when to roll out his party's new programme is a dilemma. Go too soon, and he knows Labour will steal his best tunes. Leave it too late, and there will not be enough time to sell the new vision to the public before the next election.

The party's goal, Mr Cameron said, is to "look, feel, think and behave like a completely new organisation". That will mean tackling what he called "the scandalous under-representation of women" in a party with only 17 women among its 198 MPs, and more Davids in the Shadow Cabinet than women. It won't be easy without Labour-style all-women shortlists, which Mr Cameron opposes. He will need all his charm and charisma to persuade female grassroots activists to select more women candidates; they usually vote for men.

Mr Cameron's emphatic victory should ensure his party unites behind him - for the time being, at least. But there is no guarantee that the discipline it showed under Mr Howard will last for ever. Mr Howard took over when the party was in the doldrums and an election loomed. He also had the respect of his party, something Mr Cameron will need to earn and could be lacking if he hits troubled times.

The new leader has promised not to repeat the mistakes of his predecessors by retreating to "our comfort zone" when the pressure is on. Mr Hague, Iain Duncan Smith and Mr Howard all promised a fresh start but resorted to traditional Tory tunes such as immigration and law and order to bolster their position in their own party.

It will be hard to avoid the European issue, which has already provoked tensions. One of Mr Cameron's few policy pledges is to withdraw his party's MEPs from the main centre-right grouping in the European Parliament. But the move is opposed by a majority of Tory MEPs and could reopen the old wounds which caused so much pain to the last Tory government led by John Major.

Mr Cameron, though, is already proving a difficult opponent for Labour. Plans to issue the traditional dossier attacking the policies, speeches and utterances of the incoming Tory leader were scrapped because he has given so few hostages to fortune. "It had too many blank pages on it," said one Blair aide. "His leadership campaign was vapid and vacuous."

So Labour will hold most of its fire until Mr Cameron discloses more of his policies. There is no doubt Labour regards him as a serious threat. Another Blair adviser said: "The previous Tory leaders attacked Tony. Cameron and his team are copying his strategy in opposition."

The irony is that the Tories, under the man who sees himself as the "heir to Blair," may embrace key parts of Blairism just as Labour is tiring of it. In the Blair camp, this is seen as dangerous. But it was reassured by Mr Brown's comments yesterday that he will be a "Blairite" in office - an attempt to pre-empt Mr Cameron's attacks on him as the "great roadblock" to public service reforms.

Some Blairites are worried that Mr Brown will try to ensure reforms through greater efficiency in the public services alone, without extending "choice". They fear that would allow the Tories to embrace a Blairite reform agenda, pushing Labour off the centre ground.

To succeed, Mr Cameron will need a quality beyond his control that his four predecessors have lacked - luck. They were unlucky to come up against Mr Blair, himself seen as a lucky politician. But as Mr Blair struggles to ensure the "stable and orderly transition" he has promised, the pendulum might just be swinging. Mr Cameron senses, as he said yesterday, that there is "something in the air".

Team Cameron

WILLIAM HAGUE, 44

JOB: SHADOW FOREIGN SECRETARY

Became party leader in 1997 aged 36, three years younger than Mr Cameron. Resigned after 2001 election. Return would be popular with the grass roots and in the Commons where he beat Tony Blair with wit across the dispatch box.

GEORGE OSBORNE, 34

JOB: SHADOW CHANCELLOR

Mr Cameron's campaign manager and former aide to Mr Hague. Educated at St Paul's and Magdalen College, Oxford. The third member of the close-knit Cameron team. Has had a hard time scoring points against Gordon Brown.

PATRICK McLOUGHLIN, 48

JOB: TORY CHIEF WHIP.

A former miner and NUM member. Known for instilling discipline in unruly troops. Held ministerial office under Margaret Thatcher and John Major in transport, employment and trade. Deputy chief whip since 1998

DAVID DAVIS, 56

JOB: SHADOW HOME SECRETARY

Mr Cameron praised him as a "talent'' in the party and will keep him in his present job. Crucially, the hard man who was a TA SAS officer, did not dish the dirt on Mr Cameron over the drugs controversy. Friends say he needs to become a Willie Whitelaw figure, an elder statesman able to tell the leader when he thinks he is wrong, while staying loyal.

THE OTHER CANDIDATES FOR SHADOW CABINET

Boris Johnson, 41

Likely job: Shadow Culture Secretary. Likely comeback in former job. Habit of gaffing but popular with the public.

Liam Fox, 44

Likely Job: Defence. Former party chairman and shadow health secretary. Right-wing Eurosceptic, earned a job after strong showing in the leadership race.

David Willetts, 49 Likely Job: Pensions. Supported David Davis, but wobbled towards Cameron. Expert on social security.

Caroline Spelman, 47 Likely job: Health. Toiled away in the whips' office and local government post. Caring image for 'caring Conservativism'.

Theresa May, 49

Likely job: Education. Feisty, fits in with drive for modernisation.