As they drowned their sorrows about the political scene on the Commons terrace on Tuesday, two gloomy Labour MPs announced they had reached the same conclusion. They were certain to lose their normally winnable constituencies at the next election, so they would tell their local party not to waste money on a lost cause and to save it for the attempt to regain the seat at the following election.

Yet amid the despondency and resignation in Labour's ranks, I found a tiny ray of hope. It came from David Lammy, the minister for Skills, at a Fabian Society meeting the previous night. Mr Lammy, our youngest minister at 35, is a friend of Barack Obama. He was speaking about how the lessons from his inspirational rise to become the Democratic Party candidate can revive British politics.

After 11 years of Labour rule, too many ministers sound like automatons. They have been sucked into the Whitehall machine and rarely peep out into the real world. Mr Lammy's candid speech was a breath of fresh air. Calling for an end to the control freakery which was part of the old politics, he said: "The lesson of the last year is that the political messages and methods of the 1990s are beginning to look very tired and out of date." He didn't need to mention names; most of his audience would have guessed he was talking about Hillary Clinton and Gordon Brown.

Mr Brown will probably not welcome Mr Lammy's speech but he should. His criticism of "the politics of control", made when he took questions, could be seen as an attack on a micro-managing prime minister, but it wasn't. Nor was his rejection of "triangulation" – positioning between left and right but also "above" them to move forward.

Mr Lammy was calling for a cultural revolution in our politics to reconnect it with the people, as Mr Obama has done. New Labour, he admitted, was never "a movement that filtered down to ordinary people".

Although brought up by a single mother in his Tottenham constituency, Mr Lammy said the real class issue in British politics is not "Tory toffs" but the "political class" itself. He said: "The danger, in a world where Westminster has created its own industry of think-tanks, lobbying firms, PR agencies and media outlets, is that we lose the rich diversity to a generation of politicians who have emerged not from the professions, but from within Westminster itself."

Mr Brown's handling of MPs' expenses this week suggests he will struggle to break out of the "old politics". While he understood the need to restrain MPs' pay, he allowed his ministers and aides to vote down sensible reforms to their allowances which might have restored a little public trust in politicians. David Cameron and Nick Clegg, both searching for a "new politics", seem more alive to the need to sweep the Commons stables clean.

Mr Lammy is convinced that Mr Brown can still turn things round. If Mr Obama can come from nowhere to win his party's nomination in seven months, then Mr Brown can win through in two years.

Will Mr Brown be capable of changing his ways and letting go of the levers of power, at government and party level? His critics will doubt it, saying he missed his one opportunity to offer change when he succeeded Mr Blair a year ago.

He saw the need for it – "let the work of change begin" – but didn't manage enough significant change from the Blair era. Now the Labour Government looks like a tired establishment and it will be hard to seize the "time for change" mantle back from Mr Cameron.

Mr Lammy's advice is to move on from New Labour's mantra of "strong economy, strong public services" to creating a "good society", which means radical action to tackle inequality, not tinkering with tax credits. "Only by standing proudly for our cause of a fairer Britain ... could Labour make a fight of the next election," Sunder Katwala, the Fabians' general secretary, writes in the next issue of Fabian Review.

Then again, perhaps Mr Brown's "fairness agenda" will be more radical than I think. After all, he has nothing to lose but his self-imposed chains.

Interesting? Click here to explore further