Allegations surrounding London Mayor Ken Livingstone's involvement in a late-night incident which left a man hospitalised after a 10-foot fall have been referred to a new standards watchdog.

Mr Livingstone has denied any wrongdoing after the incident which followed a row with his pregnant girlfriend.

Only by having the Standards Board investigate this matter can the question of who is telling the truth be solved

Lord Tope

The matter has been referred to the Standards Board for England by London Assembly Liberal Democrats. The board has the power to call witnesses if needed.

A finding against Mr Livingstone could see him disqualified from public office for up to five years.

Mr Livingstone believes the decision to refer the matter to the watchdog is an "abuse of the Standards Board, which was set up to deal with matters such as corruption and gerrymandering".

But the leader of the Lib Dem group, Lord Tope, said "only by having the Standards Board investigate this matter can the question of who is telling the truth be solved".

"Until this is done London's government will remain under a cloud and issues of real importance to Londoners will fail to be discussed and debated in public," he said.

Mr Livingstone has denied pushing a man over a stairwell during a row at the late night party.

'Nasty'

He gave his full version of events for the first time during a special meeting called by the London Assembly last week to quiz him on the subject.

Mr Livingstone said that the victim, Robin Hedges, had earlier "jumped" on him, bringing him to the ground in the street as the mayor and his pregnant girlfriend, Emma Beal, left the party following a row.

Mr Hedges had been wrongly led to believe by other people at the party that an argument between Mr Livingstone and Ms Beal had "turned nasty", said the mayor.

Mr Livingstone said that following the attack, he made his way back to the party with Mr Hedges following him up the stairs outside the house.

Cigarette claim wrong

He said there were lots of people on the stairs and, although he did not see Mr Hedges fall, he thought the injured man may have overbalanced as he climbed past people on the stairs.

Mr Livingstone said there were no drugs at the party and that press reports that he was drunk were inaccurate.

He had three glasses of wine, then slept from 10pm to 1am. When he woke he was told his pregnant girlfriend had been smoking, which led to the two having an argument.

Mr Livingstone told the London Assembly that it turned out Ms Beal had not actually had a cigarette after all.

The mayor's main target in his statement and answering questions was the London Evening Standard newspaper, who first printed allegations about the party.

Newspaper advice

Mr Livingstone said his advice to Londoners was not to buy the newspaper, which later said it was standing by its story and rejected claims it was engaged in a political campaign against the mayor.

Mr Hedges, 35, who needed a brain scan after the fall, initially described the fall as an accident, but later told a newspaper the mayor had pushed him over the wall.

Mr Livingstone has consistently denied assaulting Mr Hedges, manhandling his pregnant girlfriend Emma Beal, and fleeing the scene before police arrived.

Ms Beal has also denied being manhandled by Mr Livingstone.

Mr Hedges has told police he did not want to make a criminal complaint about the matter.