Brown's biggest asset Sarah goes into battle

A political wife who used to ration her attention to that role and demand more privacy than the extrovert Cherie Blair, she has been one of his most valuable footsoldiers.

A made-over footsoldier too: stepping out in spiky high heels, donning clothes by new British designers and with a new softly-groomed look orchestrated to signal that this political couple is not heading for the dust-heap without a struggle.

The Gordon and Sarah show at Manchester this week is intended to shake off the accumulated political grime of the past few months.

She is scheduled to make more public appearances at the conference as part of a quiet charm offensive. "People can be quite rude about Gordon," says a No 10 source with some under-statement. "But very few people feel badly about Sarah. She's an asset."

Last night as the Brown entourage swept into a debate, Mr Brown remembered to greet bystanders (he used to walk past them without acknowledgement). But it was Mrs Brown who lingered to wave and chat.

She also fulfils the role of the less reverent side in the partnership with a growing confidence. During one conversation in which Mr Brown's parttime adviser Bob Shrum reflected on how the polls were tightening against Barack Obama, she murmured what everyone else was thinking: "We should be so lucky!"

"There was a point at which it was felt that Gordon was seen as far more joyless and forbidding than he is," says the No10 source "He is never going to have the glad-handing, breezy touch of Blair - but people enjoy meeting him more than they expect."

Mrs Brown has combined forces with Stephen Carter - the Downing Street strategist who has emphasised the need for the PM to open up his circle.

The Browns have already embarked on a summer slim-down, with the PM re-introduced to a personal trainer. He now leaves his wineglass untouched and eats barely half his food.

According to friends, he has taken to the task with such alacrity that their only concern is that he does not overdo it. "The last thing we need now is ' haggard Gordon', " said one friend

But Mr Brown's strengths and weaknesses never really alter. He has an impressive grasp of the macro-issues which define the age - the politics of energy, population, poverty and the rise of China and India. He cannot understandwhy people do not focus on what he calls the "big questions", but he is sticky on how these relate to the day-today perception of his government and frustrated by his inability to communicate his strengths. His staff were palpably relieved when his intervention on the financial crisis last week was deemed well-judged after a string of mis-hits.

Contrary to his dour image, he is good at telling anecdotes and displays a sense of humour about the past intricacies of Labour politics (although irreverence about the present is out of bounds). I ventured once that his encyclopaedic political memory would make him a great Professor emeritus at the Kennedy School of Government one day. "I don't like the sound of that emeritus bit," he shot back.

It must be very hard to tell Mr Brown how to do things differently after all these years, assuming anyone still tries in earnest. Perhaps Sarah gets a hearing. She deserves it: the human face of the Gordon regime.