Gordon Brown has just blown his chance of becoming Prime Minister again by forgetting one of the cardinal rules of politics -- never speak your mind when in the vicinity of microphones.

Gillian Duffy , 65, a retired grandmother came across Brown on the streets of Rochdale , near Manchester where he was campaigning.T he British general election is May 6th

She explained that she had been a life long Labor supporter but she was fed up of the party now and asked him some very sharp questions including what was he doing about immigration.

Brown answered them all in seeming good form but then back in his car he did not realize a TV news microphone was still attached to his lapel.

"That was a disaster" he said blaming a junior staffer for the encounter, even though it seemed to have been completely random.

He referred to Duffy as "a bigoted woman" which she certainly was not, merely a concerned older voter worried about the country her two grandchildren were growing up in.

Brown immediately recognized the impact of the gaffe and headed straight back to Rochdale and sat with Mrs Duffy and emerged from her home to say he had been forgiven.

But it all came too late. It was front page and headline news everywhere, and it played into the most damaging view of Brown of all that he is a a bully who is deeply unpleasant to his staff and has little sense of the concerns or worries of ordinary people because he has been in power so long.

It is the most damaging of all blows, just a week before the election and Labor were already lagging.

It now seems certain that David Cameron will be the next Prime Minister.