The prospect of an imminent coup against Gordon Brown was put on hold yesterday. On the first day of Labour's conference in Manchester, delegates and Cabinet members tried to outdo each other as they proclaimed unity, praised the prime minister's handling of last week's financial crisis, and in the words of one Labour MP "sent the rebels into the shadows, at least for the next couple of days".

Manchester has been billed as Brown's "make-or-break" conference, with his scheduled leader's address on Tuesday being talked about as his last opportunity to show how he can revive his party's ailing fortunes, which have been in decline almost since last year's conference.

Trying to lessen the impact of Tuesday's speech, the prime minister gave a mini-version of what the party can expect. Brown's key message was that the financial difficulties of last week, which saw global markets tumble and then rally after government intervention in Washington and London, had shown he can still see Britain safely through the storm.

Last week's near-meltdown, which saw Lehman Brothers in New York go down, insurer AIG saved by the US Treasury and HBOS in the UK being taken over by Lloyds TSB, appeared to give Brown a new lease of life.

Having joked that the US government, through AIG, were now the shirt sponsors of Manchester United and chancellor Alistair Darling was the unlikely name behind Northern Rock's sponsorship of Newcastle United, Brown told a cheering audience the message from last week was that Labour would ensure there is future financial responsibility and not irresponsibility, and that he would do "whatever it takes" to get there.

Accused of indecision and dithering in the months that eventually led to the nationalisation of Northern Rock, Brown tried to reinvent himself as a leader of authority, quick thinking and action. With jobs and pensions at risk in the share slide of HBOS, the prime minister said: "We took immediate action."

He said the government's decision to temporarily ban the hedge fund practice of short selling of shares had been followed by similar action in the United States.

Brown is scheduled to visit Washington and New York after his speech on Tuesday, where he will discuss new ways of dealing with global finance and potential new methods of regulation. He told delegates the time had come for new ideas whose test was not a PR slogan, but a harsh test of political judgement.

For a party desperate for Brown to show some decisiveness, this may be as close as he can get. He effectively praised his own ability by taking hard but correct choices on everything from Northern Rock to the action that ended speculative market practices last week.

The chaos on world markets last week appears to have given Brown a renewed sense of purpose. A backbench MP, who said he believed "this will sadly be Gordon's last conference as leader whatever he says over the next few days", admitted there was no longer an appetite for a coup.

"This isn't the time to dump him," he said. "People outside this fan club are more interested in what happened last week and how we can prevent further chaos, than they are about who leads the Labour Party. But the share crisis has made it possible for Gordon to have a good week."

With the announcement of a £1 million donation to Labour from Harry Potter author JK Rowling, posters appeared around the conference floor. "Hogwarts for Gordon" said one. The PM himself admitted to being pleased "to have the magical powers of Harry Potter" behind him.

What powers he does hold as prime minister were exaggerated when he said he and the chancellor had been working to get the world price of oil down. With oil falling back from a high of $150 a barrel to $80 last week, Brown signalled, as though it were a spell from a Hogwarts text book, that "our efforts are now making an impact".

Brown also told the conference that he would shortly be holding talked with the administrators of Lehman Brothers about getting the return of billions of dollars transferred from London to New York days before the investment bank went under. The transfer was routine practice between London and New York branches of Lehman Brothers. But Brown's appeal suggests the action may have been deliberate and well-timed and left London employees worse off when the bankruptcy was announced.

"I hope to get this money back to pay not high-flying financiers, but the cleaners and other workers who might not be paid," he said.

New Labour, New Gordon, was being proclaimed by the prime minister. But for other members of the Cabinet the first day of the conference was about warning off the rebels.

In a question from the conference floor by a delegate called Rachel, which sounded like one of the planted questions Brown faces in PMQs in the Commons, the "indulgent issue of leadership was brought up".

Yvette Cooper, the first secretary to the Treasury, said "navel gazing" was inappropriate and the party couldn't afford to be seen "talking about ourselves". Cooper said that, in Darling and Brown, "we have the right people and we should be proud of them".

The chancellor also praised Brown's decade in the Treasury and said he still retained the "determination and the vision" to see Britain through a difficult period.

The clearest signal that the rebels should back off, not just in Manchester but till the next general election, came from the Cabinet secretary, Ed Miliband. In a powerful speech, which will mark Miliband as a potential future leader himself, he said the party had to have a leader who had "resolve, toughness, and a deep sense of fairness. And Gordon Brown has all these qualities." He told delegates they had a "duty" to support Brown's leadership.

Not everyone in Manchester's G-Mex Centre was convinced. "It's day one," said one delegate from Swindon. "We come to cheer, not to attend our own funeral. All we can hope for is that no-one tells us to go home and prepare for opposition."