Just as Number 10 hoped it would, the nascent, though leaderless, rebellion that once threatened Gordon Brown fizzled out over the parliamentary summer break. The lack of any substantial momentum that might have forced the resignation of the prime minister left the solo assault last week by the former home secretary, Charles Clarke, looking like a well-timed challenge to revive the anti-Brown rebels.

Clarke effectively said Brown had two months in which to show he could save Labour from "electoral disaster". And if he couldn't, then rather than watch his party sleepwalk to defeat, he should "stand down with honour". Clarke's intervention, though dismissed by Brown loyalists as typical and embittered, has turned Brown's promised autumn relaunch into the beginning of a season of survival hurdles that will have to be successfully negotiated. Should Brown fall at any of the major challenges ahead, the current quiet rebellion will get much noisier.

The first Cabinet meeting of the new season will take place in Birmingham tomorrow. This will be the first such gathering outside Westminster for half a century. For the hour and a half it lasts, Brown will have to convince some of the sceptics around the table that he has what one ministerial aide called "enough gas left in the tank" for the hurdles ahead.

With Brown serially insisting that the "fundamentals" of the UK economy are sound, and that Britain remains well-placed to ride out the current storms engulfing the global economy, each month between now and the next general election brings with it new figures from the Office of National Statistics.

The official inflation and unemployment figures for September, October and November are likely to add to the sense of gloom rather than offer the prospect of clear skies. The Organisation for Economic Co-operation and Development and the International Monetary Fund have both predicted slowing growth and sterling continuing to fall. This is against the recent forecasts by the Brown and the chancellor, Alistair Darling. This makes the ONS figures for Britain's third-quarter growth (which measures gross domestic product), which will be published on October 24, a key hurdle in Brown's survival race. The Q2 figures showed zero growth. If the third-quarter figures show negative growth, Britain is on course and barely three months away from falling into the formal recession the chancellor denies will happen.

According to David Davis, an economist at the Centre for Economic and Business Research, the coming negative growth figures will only confirm what people already feel. "A formal recession, two consecutive quarters of falling growth, might be academic," he said. "We are already experiencing slow profit growth, higher inflation, falling earnings growth, with real household incomes being squeezed. Unemployment is rising sharply and the overall cost of living is rising. All of these figures have become political obstacles that the government has to overcome. Every month now matters."

This week, Darling will have to explain to the TUC gathering in Brighton that their call for a windfall tax on Britain's energy companies is, in economic terms, a non-starter. The unions will not be pleased, and using Darling's recent terminology, they will be "pissed off" that wider calls to return their rights on secondary picketing are also being ignored by the government.

Tuesday September 9 Brown's speech to the TUC general council on Tuesday night, the day before he's expected to announce a package aimed at helping those struggling with accelerating energy bills, might once have been his opportunity to tell the unions how much their financial support for Labour is needed. But after his speech to the CBI in Glasgow last week revealed there was little of substance in the promised energy package, Brown just needs a speak-and-leave visit to the TUC and will move on to the next major hurdle on September 23 in Manchester.

Tuesday September 23 With a deflated party spirit and most expecting years of opposition ahead, Brown's leader's speech on September 23 needs to be special. But for one government minister who believes Brown has already overstayed his welcome, the speech, however well it's received, will mean little. "We are being delusional if we think Gordon is going to recover all that's been lost in an hour of shouting. The speeches that matter this year don't belong to us, they belong to Cameron and Osborne."

Expecting Brown to now deliver vision, charisma, and a raft of policies to turn round Labour's dire position in the polls is, as Clarke and other Blairite dissidents know, a thing of fantasy. Manchester will not mark the resurrection of Brown, but he will do well to come through it unscathed.

Brown's reaction to George Osborne's tax-reduction speech at last year's Conservative conference, followed by David Cameron's no-notes performance, is said to have contributed to Brown's decision to back away from the election that-never-was. This year's Tory conference in Birmingham holds a similar potential to deliver more damage.

Monday September 29, Wednesday October 1 Osborne speaks on Monday September 29, with Cameron closing the conference on Wednesday October 1. When the first post-conference opinion polls are published in the weekend national newspapers, Number 10, the Cabinet, and Labour's ministers will begin to get a sense of the difficult year ahead. If Labour fall further behind in the polls, Brown's conference season will be dubbed a flop and the rebellion will be very much back on.

A week later the Commons returns, and Brown's regular humiliation at Prime Minister's Questions will be back, with the first attack from Cameron likely to be the summer gaffe by Darling on the state of the economy. A Cabinet and ministerial reshuffle may already have taken place. But if Brown tries to move either Darling or Miliband, the loose unity of the Cabinet could be weakened. Given that a Cabinet revolt is the dissidents' best hope of forcing Brown to resign, any reshuffle remains a dangerous procedure for Brown.

Thursday October 30 Parliament could be back only three weeks before Brown faces the toughest test of the seasonal hurdles. Early rumours suggest the Glenrothes by-election has been pencilled in for Thursday October 30.

After the post-summer economic relaunch, his leader's speech in Manchester, a possible reshuffle and a few months of worsening economic figures, should Labour lose again to the SNP in Brown's own backyard, a rebellion would be not just back on but in full cry.

One former Cabinet minister - who said Brown was "already one of the tragic figures of recent Labour party history" - suggested that "If Labour lose Glenrothes, there will no summer break for Gordon to hide in. There may need to be a post-mortem, because the sick patient that is Labour at the moment will have become a death. What does the party then wait for - another relaunch?"

On Brown's side throughout this whole season of discomfort is the stark reality that the average age of the parliamentary Labour party is in the mid-50s. Many of the MPs predicted to lose their job when a general election comes will find it difficult to get another high-profile job. A rebellion, if it comes at all, will therefore have to come from within the senior ranks at Westminster.

May 2009 Extending Clarke's warning period from two months to eight months, with the new deadline being the European election in May next year, has been offered up as a compromise by some close to Brown. Some MPs have suggested that, rather than pin all on the Glenrothes result, the full plebiscite of the European poll will be a better test of Brown's premiership.

If Labour were to be slaughtered in May 2009, Brown would then have to stand down. A new leader could be in place before the parliamentary summer break, with an election held in November or early in 2010. So is this a real option, or are Labour just playing for more time? An MP in a Birmingham marginal seat suggested: "Playing for time is all we have left. What else should we do, I don't know. And clearly Gordon doesn't know either."