OUTSPOKEN politician Brian Coleman has infuriated the Fire Brigades Union by saying its officials were "thick, can't string a sentence together and incoherent".

The Conservative GLA member, who chairs the London Fire and Emergency Planning Authority (LFEAPA), made the derogatory comments in a north London newspaper in the wake of a series of strikes in a row over shift patterns.

Mr Coleman said: "The union are a thoroughly unpleasant and nasty lot – they always have been. They are not affiliated with the Labour Party and stories about bullying and intimidation go right back to the strike in the late 70s."

He added: "Most of the union officials, if they had half a brain cell, they’d be dangerous. Most of them are thick, can’t string a sentence together and frankly are incoherent."

Matt Wrack, general secretary of the Fire Brigades Union, said the latest rant from Mr Coleman was evidence the former Barnet mayor was finally "losing the plot", but added the union did not want to get into a slanging match.

He said: "It is important, if industrial relations in the fire service are to get back on an even keel, that we have someone sensible to talk to at the LFEPA. I have been afraid recently, as his remarks became wilder, that Mr Coleman was starting to lose the plot. It appears he has now lost it – I hope temporarily."

He added: "All the FBU officials are, or were for many years, serving frontline firefighters – I did the job for 22 years – and were elected as representatives by our colleagues in the fire service. Mr Coleman may not like us much – indeed, it appears that he doesn’t. But it’s not up to him to decide who is elected to represent London firefighters."

Mr Coleman, a ward councillor for Totteridge, was pulled up by the council's standards board in 2009 when he was Barnet's mayor, after sending a political blogger an angry email calling him a "an obsessive, poisonous individual".

At a GLA meeting earlier that year, he interrupted a fellow member by calling him an "odious toad".

And has after defeating Labour's Nicki Gavron to the Barnet and Camden seat at the London mayoral elections in 2008, he told her to "take your A to Z back to Haringey".