Alan Milburn said 'uncertainty' had to make way for 'clarity'
Labour must once again offer a message of change to win back voters, former health secretary Alan Milburn has said.
The willingness to change is what made New Labour so dominant, he wrote in a pamphlet for think tank Progress.
"Now change beckons once again," he said. Commentators say the article contains implicit criticism of the PM.
Meanwhile, a number of senior party figures have said Labour needs to "get off the back foot" and "rediscover the passion" that helped it into power.
In the pamphlet, published just days before the Labour conference, Mr Milburn said the public had reached the limits of what they would pay in taxes and said more power should be handed back from Whitehall to local communities.
Mr Milburn wrote: "One of New Labour's key strengths has been its preparedness to face the future challenge rather than taking comfort in the past achievement.
"The willingness to change is what has made New Labour so dominant in British politics and forced even our most strident opponents into contemplating changes they once thought abhorrent. Now change beckons once again."
Mr Milburn said he welcomed Mr Brown's commitment to put more power into the hands of people, but that a "splurge of Whitehall initiatives" seemed to point in the opposite direction.
"Public disengagement is a symptom of disempowerment. Too often we shut people out when we should be letting them in," he said.
Mr Milburn added: "This half-in, half-out approach won't work. Uncertainty has to make way for clarity."
He went on to praise the prime minister's predecessor, Tony Blair, for courage in transforming Labour.
But BBC political correspondent Iain Watson said Mr Milburn had been careful not to demand a change in Labour's leadership.
"He's seen as a Blairite, so any explicit call for Gordon Brown to go could prove counter-productive," he said.
Meanwhile, former Deputy Prime Minister John Prescott and former Labour communications chief Alastair Campbell have said the party can win the next election, but that it has to get "off the back foot".
Along with ex-sports minister Richard Caborn and MEP Glenys Kinnock, they wrote in New Statesman magazine: "Rightly in politics, there is an enormous focus on the party leaders. But the fight cannot be won by them alone.
"Labour needs to rediscover the passion that gave us victory in the first place, to defend our record with pride, promote our policy agenda with confidence, knowing that we are alone in having thought through policies to meet the great challenges of our time."
In an interview with the same publication, Work and Pensions Secretary James Purnell refused to condemn Labour rebels pushing for a challenge to Mr Brown's leadership.
Mr Purnell said he did not agree with them but it was "ridiculous" to pretend MPs could not complain when worried.
Pressure has been mounting on Mr Brown after Scotland Office minister David Cairns resigned on Tuesday, and 12 other Labour MPs called for nomination forms to be issued for a leadership challenge.
One of the rebels, George Howarth, described Mr Brown as the most unpopular British prime minister since Neville Chamberlain after Adolf Hitler invaded Norway.