Michael Gove has declared himself "the candidate for change" as he set out his pitch to become Conservative leader and UK prime minister.
In a clear attempt to draw contrasts with his main rival UK home secretary Theresa May - who on Thursday portrayed herself as an unshowy politician who would "get the job done" - Mr Gove said that the challenges facing Britain required "not just a cool head, but a heart burning with the desire for change ... not business as usual but a bold vision".
He said that after last week's referendum vote for Brexit, the new UK prime minister must be someone who fought on the Leave side - effectively ruling out Mrs May, who was part of the Remain campaign, even though her contributions to it were notably low-key.
Speaking at a campaign launch a day after his dramatic declaration of his candidacy forced Boris Johnson out of the race to succeed David Cameron, Mr Gove said he stood by all of the promises made by Vote Leave during the referendum contest.
"I will ensure we honour the instructions the British people have given us," said the UK justice secretary. "I argued for specific changes in the referendum campaign, I believe in them, I will deliver them.
"The promise to leave the European Union, end the supremacy of EU law and take back control of our democracy. With my leadership, it will be delivered.
"The promise to take back control of our borders. I will end free movement, introduce an Australian-style points-based system for immigration, and bring numbers down. With my leadership, it will be delivered.
"The promise to use the money we currently send to Brussels and invest it instead on the priorities of the British people - principally in the NHS - and to cut VAT on domestic fuel. With my leadership, it will be delivered."
Despite relentless controversy over Vote Leave's claims - branded "misleading" by the UK's statistics watchdog - that Britain handed £350m a week to Brussels, much of which could be spent on the NHS, Mr Gove said he stood by the pledge to put £100m a week more into the NHS.
Mr Gove's launch came as he faced calls to pull out of the Conservative leadership race from allies of Mr Johnson, as well as indications that he is being far outstripped by Mrs May in the race to secure the backing of fellow MPs.
Rival leadership contender Liam Fox said the feuding between the two men was a "distraction" and that the country needed "Brexit for grown-ups" in the wake of last week's referendum vote to leave the EU.
And veteran former chancellor Ken Clarke told BBC Radio 4's Today programme: "I do think Michael Gove would do us all a favour if he were to stand down now."
Mr Gove's announcement, shortly after being appointed Mr Johnson's campaign manager, that he had realised the former London mayor did not have the necessary qualities to be PM was "more suitable to the election of a student union than it is to be prime minister of this country at a time of pretty grave potential crisis", said Mr Clarke.
Dr Fox, the former defence secretary who campaigned for Leave, said that Mr Gove and Mr Johnson appeared to be preoccupied with the student politics of their Oxford University days.
"We are now 10 weeks away from having a new prime minister, we're in the process of electing a prime minister who will actually take us out of the European Union, and yet we seem to be permanently distracted by what can only be described as the politics of the Oxford Union in recent days," he told the Today programme.
"I think it was a distraction, we need Brexit for grown-ups and we need to be talking about the big issues."
But Mr Gove insisted that standing for the leadership was "the right thing to do".
Although he had never expected to run for the leadership, he said he allowed himself to be guided by his heart.
"I never thought I'd ever be in this position," he said. "I did not want it, indeed I did almost everything not to be a candidate for the leadership of this party.
"I was so very reluctant because I know my limitations. Whatever charisma is I don't have it, whatever glamour may be I don't think anyone could ever associate me with it.
"But - at every step in my political life - I've asked myself one question. What is the right thing to do? What does your heart tell you?"
In what seemed a swipe at Mrs May, who was widely suspected to secretly back Brexit despite being on the Remain team, Mr Gove said that in the referendum campaign
"I did not duck for cover, I did not hedge or hesitate to say what I believed. I made clear I believed in change, I believed in leaving the European Union."
He added: "I believe the next prime minister has to be on the winning side of the argument.
"Put simply: the best person to lead Britain out of the European Union is someone who argued to get Britain out of the European Union."
Mr Gove set out a broad agenda for power, including action to tackle problems with "excess pay" in the City and the boardroom.
He said the referendum had shown "in stark relief that there are two Britains: those who can reap the benefits of globalisation and those who are flotsam and jetsam in its powerful flows of global capital and free labour".
"Far too often the rewards have gone not to risk takers and job creators but insiders in our financial system and big business who have rigged the market in their interests."
Too many high-paid bosses of privatised companies did a "poor job" and "act as though they were Steve Jobs but in fact they're really behaving like David Brent", he said.
Mr Gove pledged to work across party divides to "renew and reboot" the Union between England, Scotland, Wales and Northern Ireland, following indications that Scotland - which voted overwhelmingly for Remain - may attempt to stay within the EU, possibly through a second independence referendum.
He also promised to reform public services so that those running them are rewarded "for the difference they make to individual lives" rather than for hitting targets.
And he responded to reports of a spike in racist attacks following the Brexit vote by pledging to make the UK "the most civilised, humane and progressive country on earth".
In highly-personal stretches of his speech, Mr Gove described how his "passion for change" was driven by his upbringing by adoptive parents Ernie and Christine.
His parents taught him that "if you invest love and care in any individual, you can help them to make a difference, to write their own life story".
He pointed to his changes to the school system as Britain’s education secretary and reforms of the prisons as justice secretary as an indication of the kind of transformation he hoped to achieve as PM.
Insisting he was driven by "conviction not ambition", he said: "I stand here - and I am standing for the leadership - not as a result of calculation. I am standing with the burning desire to transform our country.
"Because my heart tells me that if we are bold, if we refuse to settle for business as usual, if we dare to dream and summon up all the qualities that have made this country the greatest in the world, then for Britain - and its people - our best days lie ahead."
Answering questions following his speech, Mr Gove said he would wait at least until 2017 to kick off the two-year process of negotiating the UK's withdrawal by invoking Article 50 of the Lisbon Treaty.
Despite the agreement of the remaining 27 EU states earlier this week that they would not negotiate until they receive formal notification of Britain's intention to leave, Mr Gove said he expected to hold "extensive preliminary talks" before taking that step.
"I will only trigger it after extensive preliminary talks ... so I have no expectation that Article 50 would be triggered in this calendar year," he said.