The former Cabinet minister Alan Milburn stirred up Labour's leadership row today with a coded attack on Gordon Brown and a call for the party to embrace "change" if it wants to win back voters.

Mr Milburn's criticism, in a pamphlet for the Blairite think-tank Progress ahead of the party conference, came as an opinion poll suggested that Labour are a record 28 points behind the Tories after the latest bout of infighting.

The Ipsos Mori poll put the Conservatives on 52 per cent, Labour on 24, and the Liberal Democrats on just 12 per cent. The last time the Conservatives enjoyed more than 50 per cent support was in 1988, the year after Margaret Thatcher's third election victory.

Four Government figures have left or been sacked after protesting at Mr Brown’s performance in the last few days as the number of MPs openly demanding a leadership contest grows ahead of the party's conference next week, albeit slowly.

Mr Milburn's intervention will focus attention on the leadership split, although he has made no secret of his distaste for Mr Brown since he resigned as Health Secretary in 2003, saying that he wanted to spend more time with his family.

Labour insiders consider it unlikely that the Darlington MP could mount a successful leadership challenge, but there is a feeling that he could emerge as a "stalking horse" candidate, able to attract the 71 nominations needed to spark a leadership contest which Downing Street is steadfastly trying to prevent.

Under such a scenario, more serious candidates might then be flushed out either from within the Cabinet or among other party heavyweights.

In his pamphlet, 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.”

In an apparent dig at Mr Brown’s controversial decision to abolish of the 10p tax rate, Mr Milburn called for taxes to be cut for the low-paid. Although the Prime Minister had committed himself to putting greater power in the hands of citizens, a “splurge of Whitehall initiatives seem to point in the opposite direction”, he argued.

The pamplet also called for local people to be given more direct control over health and police services, as well as facilities such as parks and children’s centres. Mr Milburn wrote: “Public disengagement is a symptom of disempowerment. Too often we shut people out when we should be letting them in.

“This half-in, half-out approach won’t work. Uncertainty has to make way for clarity.”

As the leadership row rumbled on, ministers insisted that they were focused on their jobs. Also springing to Mr Brown's defence was John Prescott, Tony Blair's former Deputy Prime Minister who is joining forces with various Labour figures including Alastair Campbell and Glenys Kinnock, wife of the former party leader, to help calm the party's nerves before the next election.

Mr Prescott told BBC Radio 4’s Today programme: “The public is listening to Labour - all it hears it talking about is leadership. For God’s sake, they are worried about their jobs, they are worried about the future. They want somebody who can handle global problems, and Gordon Brown is that man.”

He added: “Disunity kills parties, whether it’s Tories or Labour, and after 10 years it’s amazing that we should be allowing a climate of opinion to undermine the kind of confidence in our party as to the role of a Labour government."

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