Gordon Brown broke into his meetings in Washington last night to talk a ministerial aide out of resignation over the abolition of the 10p tax rate.

In a revealing insight into his priorities, the Prime Minister rang Angela Smith, parliamentary private secretary to Yvette Cooper, the Chief Secretary to the Treasury, between his separate meetings with the three presidential contenders and President Bush.

Ms Smith had been reported to be on the brink of standing down from her unpaid post rather than vote for the measure in the Commons. Mr Brown’s allies said that they hoped to keep her from quitting and blamed the Prime Minister’s enemies for leaking her unhappiness to the BBC to try to force her hand.

Speaking later at a press conference in the Rose Garden, Mr Brown said that he would not backtrack over his tax reforms. “We are taking the right long-term decision for the British economy. We will see these changes through,” he said. He again refused to acknowledge that anyone would be worse off as a result of his abolishing the 10p rate, saying that the change was accompanied by reforms to make pensioners and other hard-up groups better off and Britain would have the lowest basic tax rate, 20p, for 25 years.

He again rebuffed questions about his leadership: “I’m sticking to the job and getting on with the job . . . I will look to do the right thing for the British people and the British economy.”

Ms Smith said in a statement last night: “It has been reported by various sources that I am about to resign from my post as PPS to Yvette Cooper. It is true I have concerns over tax changes and these have been discussed with senior government figures. I am reassured that my concerns are understood and that the Government remains committed to its anti-poverty agenda. Resignation of my post is therefore not envisaged.”

Mr Brown is facing a growing revolt from Labour MPs over the tax change. He was criticised heavily over the change in a private meeting before MPs left for the Easter recess.

Mr Brown’s intervention with Ms Smith came after the most outspoken attack so far by a Labour figure on Mr Brown’s character and style. Lord Desai said that Gordon Brown “was put on Earth to remind people how good Tony Blair was”, adding that the Prime Minister was a “worrier” who looked “weak” and “indecisive”. Predicting that a defeat for Labour in the London mayoral campaign would be “absolutely traumatic” and would intensify speculation over who should succeed Mr Brown, he said: “There would be real panic stations.” Lord Desai, a professor at the London School of Economics, refused to retract his statements, made in an interview with the London Evening Standard. He made further criticisms, saying that whereas Tony Blair was “champagne and caviar”, Mr Brown was “porridge and haggis”.

In an interview with The Times, Ed Balls, the Schools Secretary and Mr Brown’s most senior ally, appeared to hint that corrective measures could be taken in the Pre-Budget Report (PBR) this autumn. He said: “I know that Alistair Darling, Gordon Brown and the Treasury team will want to ensure that Budget by Budget, PBR by PBR, we take forward that fairness agenda because that is the core to the moral purpose of the Government.”

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