Ken Livingstone’s ‘colourful’ language has landed him in hot water again after he compared the former leader of Wandsworth Council to Radko Mladic, the man accused of the worst atrocities in Europe since World War 2.

While on a visit to Bromley on Tuesday the former Mayor of London called Edward Lister, Boris Johnson's new chief of staff, the Beast of Wandsworth and “the Radko Mladic of local government”.

In 2006 while he was mayor, Mr Livingstone got into serious trouble for comparing Jewish Evening Standard reporter Oliver Finegold to a concentration camp guard.

He was suspended on full pay for four weeks after he was found to have brought his office into disrepute for the comment.

Bosnian Serb general, Mladic, whose nickname is the Butcher of Bosnia, was flown to the The Hague this week to stand trial for crimes against humanity including the massacre of 8,000 Bosnian Muslims at Srebrenica during the Yugoslavian civil war.

Mr Livingstone reportedly said: "If Boris gets re-elected, he'll be trying all he can to please the Tory grassroots, cos they're the one's who'll pick their next leader.

"That's why he's got the beast of Wandsworth unleashed. Eddie Lister: the Radko Mladic of local government."

Mr Lister, who was Britain’s longest serving council leader until stepping down last month, told the Wandsworth Guardian the remarks were “pathetic and offensive” and said that they might be cause for legal action.

He said: "It just shows how much he is living in the past.

"If he thinks Wandsworth was a badly run place then he should look at how he managed things.

"If all he can say is something as cruel as that then that says more about him than me."

A spokesperson for Mr Livingstone defended his remarks: "With recent changes to his team, Boris Johnson has promoted the wing of the Conservative party that trail-blazed policies to move less well-off Londoners out, hold back affordable housing, and has now caused outrage by planning to charge kids to use their playgrounds.

"Ken's phrasing is always colourful but as ever he is standing up for parents who face charges for their children to use playgrounds, in a borough where affordable housing has been disregarded, and for millions of Londoners who are losing police from their streets and paying higher fares because of Boris Johnson's Conservative policies."