Mr Cameron capped a successful Conservative conference in Blackpool with a fluent 68-minute speech delivered almost entirely without notes and ranging easily across the full range of government policies.
Delighting his party faithful by demonstrating his own growing prime ministerial credentials, he challenged Gordon Brown: "Call that election. We will fight. Britain will win."
Labour last night attacked Mr Cameron's speech as "lacking economic credibility", but it is not yet certain the two parties will battle it out in an election.
Mr Brown, who marks his 100th day in office today, will spend the weekend studying polling data collected after Mr Cameron's speech, and could announce on Tuesday that he will call a general election on 1 November.
The Prime Minister's lead in the polls has already dropped six points following Labour's conference, according to a previously unpublished poll.
A survey for IPSOS-MORI on Wednesday last week, immediately after Mr Brown's keynote speech at Bournemouth, showed Labour's lead had surged to 13 points. However, enthusiasm for the government had dampened by Sunday, the first day of the Tory conference, with the same polling company showing the Tories just seven points behind.
While Tory MPs and activists insisted they would relish the contest, some senior Conservatives last night suggested Mr Cameron's performance and a well-run conference could cut Labour's poll lead, making an autumn election less likely.
David Mundell, the shadow Scottish secretary, writing in The Scotsman, said: "David Cameron didn't bottle it, he triumphed, and now there is every chance Gordon Brown will bottle it."
Echoing Mr Brown's recent appeals to natural Tories, Mr Cameron made an appeal to his opponent's supporters. Labour, he said, are "not bad people with bad intentions", but their "top-down" approach to politics and government had failed.
And, in a pointed contrast to Mr Brown's formal speech last week, Mr Cameron was visibly relaxed as he walked the stage.
Building on a central theme of giving people and public services more responsibility and freedom from central government, Mr Cameron sought to contrast his approach with that taken by Labour since 1997.
Mr Cameron addressed his party's traditional "core" policies of lower taxes, lower immigration and stricter criminal justice policies, yet did not back away from the environmental agenda which has upset many of his followers. He said: "Some people say it is not popular to talk about green issues. I don't care. It's right, and it falls to this generation to deal with it."
The Eton-educated son of a Berkshire magistrate and an Aberdeenshire stockbroker also confronted Labour attacks on his privileged upbringing. "I am not about to apologise because I had a great education," he said, adding he wanted all children to have similar quality schools.
And he ended with a sharp challenge to Mr Brown to call the election and "let people decide who can make the changes we need in our country".
'Knackered' leader's gaffe
DAVID Cameron may not have wanted everyone to know that he refers to his wife as "babe" or that 67 minutes of non-stop oratorical acrobatics had left him "knackered", but such are the perils of microphone mishaps.
Having completed his speech the party leader failed in the simple task of making sure that he was out of earshot before chatting away to colleagues and wife Samantha.
Mr Cameron could be heard asking members of his shadow cabinet: "Was that all right?" as the crowd applauded.
He asked his wife, Samantha, the same, adding: "I love you babe."
Moments later, he said: "Ahh, I'm knackered."
“New world, old politics failing – change required. That is what we’ve got to be about today.”
“I think at the next election we will be able to offer people the strongest family package any party has put together. Yes, we’ll recognise marriage in the tax system.”
“What we must be is the party of sensible green leadership.”
“I’m the son of a magistrate and a stockbroker, but the great privilege of my upbringing wasn’t the wealth, it was the warmth, it was the family.”
“So Mr Brown, what’s it going to be? Why don’t you call that election?”
• NOT a wet eye in the house yesterday as the Tories, and British politics, bade farewell to Blackpool. None of the major UK parties have any plans to return to the Lancashire seaside resort, preferring major cities like Manchester and Birmingham, which offer modern, comfortable hotels and significantly less risk of developing either food-poisoning or scurvy. Good riddance.
• TRANSFORMATION of the week: Michael Gove. The Tory schools spokesman has ditched his trademark jam-jar spectacles for smart new contact lenses. The effect would be impressive if he could just stop blinking and crying.
• LAST wheeze from the lovely people in the Tory press office as hacks were yesterday presented with bright blue egg-timers.
No-one knows why, and in our desperate rush to leave Blackpool forever, no-one thought to ask.