Gordon Brown's campaign suffered a self-inflicted blow when he was forced to apologise publicly and in person after branding a pensioner "bigoted".

Mr Brown went to 65-year-old Gillian Duffy's home in Rochdale to offer his personal apology. He emerged after almost 45 minutes to declare himself a "penitent sinner" who was "mortified" at what he had done.

The Prime Minister's comment - caught on microphone as he drove away from a campaign event in Rochdale - overshadowed Labour's efforts to highlight their policies on crime and the economy.

And the row interrupted Mr Brown's preparations for Thursday's crucial TV debate, when he will come under even greater pressure as he goes head-to-head with David Cameron and Nick Clegg for the third and last time before the May 6 General Election.

Mr Brown's gaffe came after he was buttonholed by former council worker Mrs Duffy, who asked him a series of questions about the economy, tax, universities and immigration.

The discussion ended amicably, and the widow - who said she was a lifelong Labour voter - said she had found the PM "nice" and intended to vote for him by post. But as Mr Brown was swept away in his car, he told an aide the encounter had been "a disaster", unaware that his words were being transmitted by a Sky News radio microphone which he had forgotten to remove.

"That was a disaster," the PM said. "They should never have put me with that woman." Asked what Mrs Duffy had said, he replied: "She was just a bigoted woman."

When informed of his comments, Mrs Duffy said she was "very upset" and wanted an apology.

Mr Brown later apologised during a live interview on BBC Radio 2, saying he had been frustrated at not being able to answer Mrs Duffy's questions about immigration. The PM then phoned Mrs Duffy, before breaking off from preparations for the TV debate to drive from Manchester to Rochdale to speak to her in person.

Following their private meeting at her home, he told reporters: "I am mortified by what has happened. I have given her my sincere apologies. I misunderstood what she said. She has accepted that there was a misunderstanding and she has accepted my apology. If you like, I am a penitent sinner."

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