'He overbalanced and fell. It was an accident'

Mayor faces the London Assembly to deny assaulting his partner and her friend at a party

Ken Livingstone sought to draw a line under the affair that has threatened his political career yesterday when he gave the fullest account yet of his "fracas" at a late-night party.

Speaking to an emergency meeting of the London Assembly, the Mayor of London denied he had assaulted either his pregnant partner, Emma Beal, or one of her friends at the event last month.

Mr Livingstone, who was asked to appear after theEvening Standard newspaper contradicted his previous account of the party to the Assembly, stood by his story and urged the paper to stop "harassing" Ms Beal.

The Mayor denied assaulting Robin Hedges – who needed a brain scan after falling down a stairwell – at the party, alleging that Mr Hedges, who works for the Standard's ES magazine, had assaulted him.

Although he accepted he had had a row with Ms Beal over claims that she was smoking, he denied manhandling her. Mr Livingstone also denied fleeing before the police arrived and rejected claims that he had tried to cover up the affair using Greater London Authority resources.

After the meeting yesterday, the cross-party Assembly said it did not have sufficient evidence to refer the matter to the Standards Board for England and called on the newspaper to "put up or shut up".

Despite the Evening Standard claiming to have a sworn statement from a witness, the paper refused last night to complain to the Standards Board, a new body set up to investigate breaches of conduct.

As the newspaper is the only body to have access to any evidence, and Mr Livingstone has refused to sue the paper or take it to the "toothless" Press Complaints Commission, any sanctions against him look unlikely. Mr Hedges has refused to press charges and the police say the matter will not be investigated further.

Under the whistleblowing code of the Greater London Authority, members have to have "reasonable evidence of sufficient weight and quality" to refer a matter to the Standards Board. Mere knowledge of allegations was not enough, its spokesman said.

Mr Livingstone said in a statement he was breaking a 20-year-old personal policy of never commenting on his private life to correct the "outright lies" told about the party. He said he went to the party with Ms Beal and drank three glasses of wine. At about 10pm he began to feel tired and slept until 1am. He woke up and danced twice with Ms Beal but they later rowed after he heard from another person that she had smoked a cigarette.

As the couple left to go home, Mr Hedges, a close friend of Ms Beal, chased them down the street, believing they were rowing and was "waving his arms saying 'help help'", Mr Livingstone said. "He then jumped on me, technically an assault, and brought me to the ground," he said.

The Mayor said he eventually got up to return to the house. In his most crucial testimony, he said he clearly remembered struggling to get up a set of steps crowded with people. As he knocked on the door, he heard a woman say that someone had fallen over.

"I did not see it, my face was turned 180 degrees away from what happened. I have not the slightest doubt that he struggled to get up the stairs, trying to get round people. He overbalanced and fell ... I didn't push him, nobody pushed him. It was an accident," he said.

Mr Livingstone said "Londoners will be my jury" and made clear he would contest the mayoral election in 2004.

Veronica Wadley, the Standard's editor, said last night that the Mayor had admitted for the first time he had had an argument with Ms Beal and had been involved in a tussle with Mr Hedges, who had tried to intervene. "As the days go by, Mr Livingstone gives us more crucial information about the party. It is now for Assembly members to decide how to tackle the issue, which has reflected poorly on the Mayor's office," she said.