New Labour strikes back: Mandelson and Milburn join Blair in attacking Miliband

Alan Milburn and Peter Mandelson backed Tony Blair's attack on Ed Miliband's leadership today, in an intervention which ratcheted up the pressure on the Labour leader.

The criticism came after a New Statesman article in which Blair warned the current opposition leader he was drifting to the left on welfare and spending.

"Tony is saying what he has always thought – that the old dividing lines between the uncaring Conservative cuts and Labour spending has got to be redrawn for new times," Mandelson told the Independent.

"I suspect the two Eds realise this. Their call for 'one nation' is the right starting point, but there are major structural challenges and choices facing Britain and Labour must consider the difficult changes and reforms needed to address them."

Alan Milburn, who along with Mendelson was one of the key architects of the centrist new Labour project, joined in the attack.

"The closer the election comes, people will stop asking Labour what it is against," he said.

"They will want to know what Labour is for and what, if elected, it would do. Tony Blair is right to argue that the sooner that process begins in earnest, the better."

Lance Price, Labour's former communications director, said: "With the death of Margaret Thatcher there has been much talk of conviction politicians, those capable of changing the weather.

"Ed Miliband aspires to be one. But he can't afford to follow Thatcher's example by becoming a radical only once in office. Labour will sleepwalk to defeat if it doesn't set out its new vision now."

Miliband hit back at Blair in an unusually combative response yesterday, saying he was trying to address some of the things Labour got wrong in power – a comment interpreted as a dig at Blair's record on immigration.

"I am leading in my own way," he told the BBC.

"I always take Tony Blair very, very seriously, but I think what the Labour party is doing under my leadership is moving on and moving forward."

There have long been mutterings about Miliband's leadership since he pipped his brother to the post after the party's general election defeat in 2010, but generally the Labour leader has been credited with maintaining party unity when it could easily have fallen into disorder.

While Miliband's polling numbers are solid, most analysts point to his low personal ratings among voters and a continued preference for the Cameron/Osborne Treasury team over the Miliband/Balls team.

The current point of criticism from senior Labour grandees is arguably the most serious threat to the Miliband strategy since he took over.