Boris and Ken in Lift Bust-up

Boris Johnson and Ken Livingstone have been involved in an angry confrontation in a lift at a London radio station. London's mayor was said to be "red with rage". The two men squared up to each other "nose to nose". Sources claim Johnson called Livingstone a "f** liar".

Tension between the two mayoral candidates surfaced during a 60-minute debate hosted by LBC 97.3's Nick Ferrari. Johnson questioned Livingstone's spending record during his eight years at City Hall betwen 2000 and 2008.

The Conservative mayor accused his predecessor of spending council tax payers money on shoes and cognac. Livingstone hit back with a claim that Johnson's transport authority, Transport for London, was facing a police manslaughter probe over the death of two cyclists at an accident blackspot.

But it was a call from a listener asking about Livingstone's tax arrangements which provoked the explosion. The Labour candidate has admitted channeling his income through a company to attract a lower rate of tax.

But when Livingstone accused Johnson of doing the same, the mayor called him "a barefaced liar". Johnson appeared furious as he left the studio and the confrontation between the two men became even more heated in the lift.