British Foreign Secretary David Miliband today set out his vision of how Labour can win the next election, insisting the party needs to offer “real change”.
Mr Miliband said Labour needed a “summer of introspection”, adding the “starting point is not debating personalities”.
The timing of the article as much as its substance led political commentators and newspaper editors to interpret it as laying the ground for a possible challenge to Brown, who succeeded Tony Blair little over a year ago.
An aide to Brown described the leadership talk as "midsummer madness" and said it would settle down in the coming months.
Mr Miliband is seen as a front-runner to succeed prime minister Gordon Brown, who is coming under increasing pressure to resign.
Writing in The Guardian, Mr Miliband said: "New Labour won three elections by offering real change, not just in policy but in the way we do politics.
“We must do so again. So let’s stop feeling sorry for ourselves, enjoy a break, and then find the confidence to make our case afresh.”
He warned the party must not yield to “fatalism”, arguing that the next election can still be won.
And he called for a more mature relationship with the electorate with the politicians needing to be more humble about their shortcomings.
Mr Miliband did not make any overt criticism of the prime minister, but neither does the article suggest Mr Brown is the only man for the job.
Asked about his article today, Mr Miliband dismissed the talk of any challenge to Brown, saying it was meant as a critique of the Conservatives. But he also gave Mr Brown less than a ringing endorsement.
"Gordon Brown is the leader of the Labour Party and he will lead us forward to address the big issues," he told Sky TV when asked if he thought Mr Brown should go.
He said that with hindsight the government should have started NHS reforms sooner and planned better for how to win peace in Iraq. And he said the government needed a “clearer drive” to tackle climate change and cut energy bills, with a low-carbon, energy-efficient economy.
In his article, Mr Miliband attacked the Conservative leader for lacking a “restlessness for change”, accusing him of being a “a politician of the status quo”.
He added, unlike with former leader Margaret Thatcher, it is not clear what Mr Cameron stands for.
“Every member of the Labour Party carries with them a simple guiding mission on the membership card: to put power, wealth and opportunity in the hands of the many, not the few. When debating public service reform, tax policies or constitutional changes, we apply those values to the latest challenges."
“What is on Cameron’s party card? What is his vision for Britain? He doesn’t have one.”
The remarks come after Leader of the Commons Harriet Harman was forced to deny plotting against the prime minister.
She insisted she was not preparing a campaign to take over at Number 10, and reiterated her loyalty to Mr Brown. She also rejected reports that in the wake of the Glasgow East by-election defeat she had been overheard telling aides: “This is my moment.”
Pressure has been increasing on Mr Brown since last week’s ballot box humiliation, with several backbenchers openly calling for him to consider his position.
There have been reports that around 10 junior government members could quit in protest if the prime minister does not agree to step down soon.
Agencies