Peter Mandelson admits he overdosed on his complex relationship with the media in a new TV documentary.

The former Northern Ireland secretary reveals in a BBC programme on Tuesday that he had become addicted to attention, breaking one of his own rules.

Paraphrasing a famous quote by former US president Bill Clinton, he says: "I committed the mortal sin with good publicity. Instead of just enjoying it, I inhaled. And I think I probably inhaled a bit too much."

In the programme, presented by Mirror editor Piers Morgan, the MP for Hartlepool claims he was a victim of trial by media.

"Before you know where you are, you are found guilty, you know, at the bar of the media. Now is that justice?" the man who was once Labour's head of communications says.

Mandelson tells for the first time what happened in Downing Street when the prime minister sacked him for a second time in 2001 over the Hinduja passport affair.

"I said, 'Are you going to destroy my entire political career, if not my life, on the basis of one morning's newspaper headlines?'

"And he looked pained, very pained - as I'm sure he was - and said, 'I'm afraid I don't think I have any alternative'."

Mandelson also reveals that the prime minister advised him, one of his closest political friends, to undergo a "personality transplant" in a bid to repair his career after his first resignation over a home loan.

"He sat down and he wrote out for me in his own hand on a piece of paper what I needed to do to put things right for myself - what changes I need to make to my life, my persona, how I dealt with the media, my relationships, the whole lot. It was a marvellous personality transplant," Mandelson says.

Mandelson, who was forced to quit as DTI secretary in 1998 over a £373,000 home-loan, accepts it was "a legitimate story" for journalists to follow but remains convinced he did not act improperly over the passport application from the Hinduja brothers.

Morgan highlights the fact that his treatment of some journalists while he was working to create New Labour's image might have contributed to his downfall but Mandelson is unrepentant.

"It wasn't my job to put out bad news about the Labour Party," he says.