Boris Johnson has said it is time to "let the British lion roar" as he called for Brexit to be a moment of national renewal.
The foreign secretary told Tory activists the UK "can win the future" and should stop treating the referendum result as if it were "plague of boils".
In his speech, he praised Theresa May's "steadfast" leadership over Europe.
And he insisted the whole cabinet was united behind her aim of getting a "great Brexit deal".
In a tub-thumping speech which was cheered by Tory activists, he played down claims of Brexit divisions, saying he and his colleagues agreed with "every syllable" of the PM's recent Florence speech about Brexit.
And he suggested that the UK's best days lay ahead once it left the European Union.
"We can win the future because we are the party that believes in this country and we believe in the potential of the British people.
"We are not the lion. We do not claim to be the lion. That role is played by the people of this country. But it is up to us now - in the traditional non-threatening, genial and self-deprecating way of the British - to let that lion roar."
Mr Johnson's highly-anticipated speech, which Mrs May is reported to have read in advance, followed criticism of his recent interventions over Brexit, which have prompted speculation about a leadership challenge and led to calls from some MPs for him to be replaced.
The foreign secretary took aim at Labour's claim that it had won the snap election which saw the Tories lose their majority, pointing out that it had won nearly 60 fewer seats than the Conservatives.
"Jeremy Corbyn didn't win. You won - we won. Theresa May won.
"She won more votes than any party leader and took this party to its highest share of the vote in any election in the last 25 years and the whole country owes her a debt for her steadfastness in taking Britain forward as she will to a great Brexit deal."
Amid talk of continuing cabinet division over the terms of the UK's exit, he said he shared the PM's goal of creating a "deep and special partnership" with the EU after it leaves and believed that the UK would remain a "quintessential European nation".
"Based on that Florence speech on whose every syllable, I can tell you the whole cabinet is united," he said.
"Since it is manifestly absurd to argue that European values or culture or civilisation are somehow defined or delimited by the institutions of the EU, we will be no less European. Britain will continue to be European in culture, geography, history, architecture, spiritually, morally, you name it."
Throwing down the gauntlet to Labour, he joked Jeremy Corbyn was "Caracas" for his support for socialist regimes in Venezuela and elsewhere.
But, Mr Johnson said, at the same time as the Conservatives defended the benefits of free markets they must do more to make capitalism "work better" for people.
"We may have the most illustrious battle honours of any political party but now we have to win the battle for the future," he said. "The way to win the future is not to attack the market economy, not to junk our gains but to make it work better."
"Make it work for all those who worry their kids will never find a home to own and make it work better for parents who can't find good enough childcare."
Mr Johnson's Labour shadow, Emily Thornberry, said mentions of the Yemen crisis, and Saudi Arabia's role, had been "conspicuous by their absence" in his speech.
In the run-up to Mr Johnson's speech, the prime minister insisted she was in charge of the government and Brexit negotiations but believed a range of voices around the cabinet table made for better decision-making.
"I think leadership is about ensuring you have a team of people who aren't yes men," she told the BBC.
Mr Johnson was one of a succession of top Tories to bang the drum for Brexit on day three of the conference. International Trade Secretary Liam Fox called for an end to "self-defeating pessimism" while Brexit Secretary David Davis urged people to disregard the noise coming out of Brussels and "keep your eyes on the prize".