Tony Blair's two closest advisers once came to blows in a row over what he should wear to do a doorstep appearance, Alastair Campbell's diary reveals.

Mr Blair was forced to pull Peter Mandelson and Mr Campbell apart "like a dad trying to shush two squabbling brothers", the former No 10 communications director writes.

The incident happened in a hotel room in Brighton in February 1995 as Mr Campbell was trying to write a speech for Mr Blair to give to a Labour conference, says Mr Campbell.

Mr Mandelson insisted that Mr Blair should dress casually in cords and an open-necked shirt to go down and talk to a group of Young Labour activists, while Mr Campbell said that it should be a shirt and tie, if not a suit.

"I felt it was another instance of Peter winding TB up over total trivia," writes Mr Campbell. "The speech was a priority. His shirt wasn't."

He describes how Mr Mandelson exploded at being contradicted, saying he was sick of being rubbished and undermined, that he hated it and he wanted out.

Mr Campbell suggested that if he wanted out he should just leave, and Mr Mandelson said that that was just what Mr Campbell wanted, to get rid of him.

"He started to leave then came back over, pushed at me, then threw a punch, then another. I grabbed his lapels to disable his arms and TB was by now moving in to separate us and PM just lunged at him, then looked back at me and shouted: 'I hate this. I'm going back to London.'

"He went off and he was still shouting at me from the corridor, saying I was undermining him and Tony, and I'm thinking who the hell might be out there hearing or watching all this."

Mr Blair went off and saw the Young Labour group - Mr Campbell does not record what he wore - then took Mr Mandelson off for a walk, writes Mr Campbell.

"It was like a classic family explosion, grim and upsetting at the same time, but afterwards leaving the air clearer and people getting on better."

Mr Campbell at first didn't want to talk to Mr Mandelson to apologise, but Mr Blair insisted that he should because, he said, Mr Mandelson was at the end of his tether. The row ended when the two had "a perfectly nice little chat".

Mr Campbell commented: "I think we both felt a little ashamed we let it get out of hand. Wrote this in the bath. What a bloody day."

Tensions in the Campbell-Mandelson relationship is one of the underlying themes in the diary.

In a later extract from December 1998, Mr Campbell writes of the then Secretary of State for Trade and Industry: "He had done the office very much to his taste, modern and brightly coloured furniture, a minimalist desk, nice pictures. A Christmas card from Prince Charles had pride of place on his desk…. How many times had I warned him that what I call his 'lifestyle ambitions' would do for him? His desire to be famous and mingle with the rich and the great and the good. What the f**k was Charles's card doing there like it was the biggest thing in the mailbag?"

Indeed, Mr Mandelson's "lifestyle ambitions" did do for him - he was forced to resign that same month after it emerged that he had bought a home in Notting Hill with an interest-free loan from Geoffrey Robinson, a millionaire Labour MP.

Two years later Mr Mandelson was forced out of Cabinet for a second time over accusations - later dismissed by an independent inquiry - that he had improperly interceded on behalf of an Indian businessman seeking British citzenship. He is currently the EU Trade Commissioner.

Times Recommends

• Swine flu vaccine for all as drug rushed through
• Artificial sperm and the race to build a baby
• BBC jets out stars to tout for prizes