London Mayor Ken Livingstone has launched a stinging broadside at a Channel 4 documentary analyzing his eight-year tenure in office, branding the show a "hatchet job."

Dispatches: The Court of Ken appeared on a Channel 4 during Monday night at 8pm, in which New Statesman political editor Martin Bright highlights the lack of accountability facing the capital's leader.

The programme also reportedly tested the mayor's drink at a public meeting and alleges that it contained whisky. Bright also claims that Livingstone's drinking habits have attracted criticism from fellow politicians.

However, a spokesman for the Livingstone campaign denounced its claims as "ludicrous" and accused it of "smearing" the Mayor.

A mayoral statement claimed Dispatches had been "totally discredited" after documentaries on Aids and climate change.

"It has been pointed out to Channel 4 in the clearest possible terms that the allegations against Ken Livingstone, in the hatchet job on him by journalist Martin Bright for Dispatches, are equally ludicrous," it said.

Its reported interviewees include the mayor's former senior adviser on Asian issues, Atma Singh.

The campaign spokesman dismissed Singh as an "embittered ex-employee". He said Singh was dismissed after failing to respond to a written request for assistance from the Metropolitan Police anti-terrorist squad in February 2005, and then failed to report the request to the GLA. He said Singh also failed to contact City Hall following the terrorist bombings on July 7 2005.

He added: "Channel 4 should apologise to Londoners for this gross attempt to interfere in its Mayoral election."