Former minister and Gordon Brown's university flatmate Nigel Griffiths has called on Charles Clarke to stop attacking the prime minister.

The Edinburgh South MP said that Clarke was "bitter" over losing his job as home secretary and that he should concentrate on contributing to a "better government."

In an interview with ePolitix.com, ex-minister Griffiths said that Clarke would regret his string of interventions criticising Brown.

Griffiths said: "Charles Clarke's comments are not just unhelpful but unfair and I'm not sure that on reflection and when writing his memoirs he might reflect on this period and think he could have been fairer.

"Gordon Brown has always been fair to Charles Clarke and we need Charles now to focus on the positive contribution to his country.

"I think he did many good things but he is bitter about the way in which he stopped being home secretary but that's the way the cookie crumbles in politics.

"What he should do is get on and deploy his considerable talents now into making this government a better government and into making this country a better country."

Asked why Clarke has rejected the conciliatory noises that came from Downing Street when Brown first came to office as prime minister, he said: "He hasn't asked my advice but I hope he doesn't think that my advice to work on improving the government are in any way patronising or unwelcome."

Griffiths also said that Brown has had no difficulty adapting from being chancellor to premier.

"He settled into the role of prime minister from day one when he had to deal with the flooding, blue tongue and a whole host of unexpected issues where his calm authority and also his Rolls-Royce brain, his ability to analyse a situation and call in people who are experts has been proven," Griffiths said.