Bigotgate threatened yesterday to push Labour’s election campaign off the rails, but Political Editor Chris Lloyd wonders if Gordon Brown can turn it to his advantage.

AS front doors go, Gillian Duffy’s is unexceptional. It is white uPVC, four panels with a semi-circular glass feature. It has a generous gold letterbox, nice and wide so the paperboy can get the Sunday supplements through without scraping his knuckles.

The door is, if you are really interested, known in the trade as a Carter One Maryland Clear. It costs £276.60, plus VAT and delivery.

You must have seen it. For 39 long minutes yesterday afternoon as Bigotgate broke, Britain’s live news channels broadcast the door doing what doors do best: staying shut.

How Gordon Brown must have wished he’d kept his trap shut, too.

How Gillian Duffy must have wished that before stepping out of her door yesterday morning for a gentle ramble around Rochdale, she had sold sponsorship on it. If she’d had the foresight to install one of those moving digital displays that you get on the side of buses, she would have made a fortune.

“Ron’s Rochdale doors: for all your door solutions… Rochdale College: disaster management course, booking now.”

Perhaps it says much about the quality of our political debate that a closed door can generate so much coverage. The commentators, bloggers, broadcasters and tweeters weren’t interested in the nature of Mr Brown’s original exchange with Mrs Duffy – she raised some perfectly reasonable points and he answered them fairly well.

They were only interested in his unscripted, unguarded comment that “she was just a sort of bigoted woman” which had caused him to be holed up behind her front door, apologising profusely.

But while the comment sheds no light on his policies, it reveals much about his personality.

Mr Brown is not the first politician to be caught out by an open microphone.

“My fellow Americans, I’m pleased to tell you today that I’ve signed legislation that will outlaw Russia forever,” said Ronald Reagan in 1984.

“We begin bombing in five minutes.”

That was a joke, and did little harm to Mr Reagan at home, though the Russians were not amused.

In 1993, John Major was caught calling the anti-European rebels in his Cabinet “bastards”.

They were only politicians, so most people agreed with him. The revelation of a steely side to his nature may even have helped grey John.

In 2006, George W Bush was caught discussing international affairs with Tony Blair in his usual, delicate, insightful fashion. He said: “What they need to do is get Syria to get Hezbollah to stop doing this sh*t.” But that was just Mr Bush being Mr Bush.

The irony for Mr Brown is that his encounter with Mrs Duffy only came about because he’d changed his campaign tactics. David Cameron chided him for apparently running from “safe house to safe house” and so Mr Brown decided to get out more into the open.

But the open is a dangerous place for a politician at election time. It was in the open, of course, that John Prescott landed his punch on countryside protestor Craig Evans in 2001. A few days later, Tony Blair was caught in the open outside a Birmingham hospital with Sharon Storer tearing into him about the treatment her partner, who has cancer, was getting.

But neither of those events proved damaging in the polls.

Despite being shown to be surprisingly out of touch by Ms Storer, Mr Blair secured a second landslide.

Despite Mr Prescott’s worst fears that the punch had ended his career, when Mr Blair explained it away as “John is John”, it enhanced Prezza’s reputation as a bruiser. Indeed, Mr Prescott sees it as a badge of honour – his 2008 autobiography was called Pulling No Punches.

CAN Mr Brown get through Bigotgate?

Can he turn it to his advantage? He is, afterall, an extraordinary survivor. He still stands having overcome three coup attempts in two years, as well as the deepest recession for decades, plus one of the greatest Parliamentary scandals – expenses – for centuries.

In fact, when he was lampooned for his poor handwriting and his insensitive spelling mistakes in a letter to a dead soldier’s mother, his poll rating improved because the public felt the attack was unfair.

When Bullygate broke, the commentators, bloggers and tweeters were outraged, but the public accepted that to be Prime Minister you probably needed a nasty streak.

If the public are generous, they’ll think we all mutter things under our breath and pray no one hears. If not, they’ll come to regard the picture of Mr Brown in the Radio 2 studio, head apparently in hands, as the defining image of the campaign.

As he heard the tape, he looked like a man breaking. An open microphone at that moment may even have caught him saying “the horror, the horror” to himself as he realised what he’d become: a unpleasant bully who blames others and has no common touch.

Ever the survivor, Mr Brown pulled himself together. When Mrs Duffy’s white door opened after the cameras had lingered on it for 39 minutes, he barrelled out, beaming. “I am a penitent sinner,” he said.

During Mr Brown’s two-and-a-half year premiership, whenever one door has closed, another has shut in his face – but he has, somehow, managed to get through.

Until now. Mrs Duffy’s Carter One Maryland Clear looks like a door too far. It may even be marked “exit”.