His party is the runaway favorite to lead the next government. All week, Mr. Cameron has urged humility on his center-right Tory party and warned that victory in elections to be held before May 2010 is not assured.
He may have a point. Though recent polls show the Tories between 12 and 15 points ahead of the incumbent Labour Party, any Tory disarray in the election runup could result in a hung parliament, where Cameron does not have an outright majority or controls only a narrow advantage.
The sheer scope of the task facing Cameron remains daunting. His party need to gain 117 seats to win a parliamentary majority of just one.
"The situation is dire for Gordon Brown; the party is in a rut," says Gavin Hayes, general secretary of Compass, a grassroots Labour lobby group. "But the election may be much closer than the polling suggests, especially if people conclude that Cameron's claim to [be] a friend of the poor and public services simply isn't true."
Nevertheless, Cameron's choice of Manchester -- in the Labour heartland of northern England -- for his party conference has underscored the dominant political narrative of a busted Labour government led by a tired Gordon Brown.
Powerful voices have joined the Cameron bandwagon. Rupert Murdoch last week switched the allegiance of his 3 million-circulation tabloid, The Sun, to the Conservatives. Yet there are still obstacles blocking Cameron's path to No.10 Downing Street.
Popular by default?
A Populus poll commissioned by The Times newspaper ahead of the Manchester conference found that, while Cameron is personally popular, the Conservatives are doing well more because of Labour's unpopularity than their own pulling power.
The data are a reminder of the work to be done to banish the "nasty party" tag foisted on the Tory governments of the 1980s and '90s, positioning them as the enemy of the downtrodden and the public services they rely on. Now, Cameron is trying to project an image of modern, compassionate Conservatives.
Suspicions also remain over the posh backgrounds of Cameron and his cohorts. Both he and right-hand man George Osborne attended Eton (a top fee-paying school) and are Oxford University alumni. The pair this week sought to distance themselves from embarrassing details about their membership in an elitist drinking club at Oxford.
In an election that will center on the economy, the Conservatives hope to make gains by speaking with the greatest authority and frankness about public-sector spending cuts and potential tax hikes.
They are necessary, they say, because of a hulking national debt accrued by a profligate Labour treasury.
Taking the conference floor on Tuesday, Mr. Osborne, who would hold the purse strings in a future Cameron government, said a freeze on public-sector pay for millions of workers will be necessary.
"Labour created this mess, and we Conservatives are going to have to sort it out. We are sinking in a sea of debt, and we need to rescue the economy from the feckless irresponsibility of the last 12 years," he said.
That stirred an immediate response from teachers and nurses' unions who claimed that a "hysterical" Cameron government will slash-and-burn school and hospital budgets.
Abroad, Cameron's problems are also mounting. Ahead of the conference, the ritual squabbling between Conservative Euroskeptics and Europhiles - those who want out and in the European Union - threatened to spill into open war.
Cameron was forced to play down suggestions of a rift in party policy toward a European Union Treaty referendum, an issue brought to the fore by Irish voters over the weekend who decided to accept the terms of the Lisbon Treaty after rejecting it last year.
The Tory leader had previously promised British Euroskeptics their own referendum on the treaty if his party wins power. But he has appeared to backpedal on that pledge, aware of making Britain the only nation standing in the way of ratification of the 27-member treaty.
Cameron's European alliances have also caused a stir. He became Tory leader in 2005 on a promise to break with the decades-old Conservative alignment with the center-right in Europe.
In June, he repositioned his members of the European Parliament with the European Conservatives and Reformists. That caused consternation among Europe's major players, who see the faction as a group of dubious right-wingers determined to block further integration of the European Union.
He also accused Mr. Zile of celebrating the Latvian Waffen-SS. Both Mr. Kaminski and Zile vigorously refute Miliband's claims.
This week's tussle over the Lisbon Treaty was a reminder that Europe remains an elephant in the room for Cameron's party.
Yet Downing Street beckons – if Cameron can prevent a damaging round of infighting and convince the electorate he can lead an economic recovery and jobs growth while protecting public services. "We will not let Britain down," he said on Monday.