Aslef's general secretary Shaun Brady was also involved in the row

The disturbance, which involved the union's top officials, took place at a party at the union's Hampstead headquarters in London on 20 May.

An internal report into the incident suggested the president and the general secretary, Shaun Brady, should face disciplinary action.

Mr Samways was suspended last month while investigations were carried out.

Self-destructive culture

In a statement, Mr Samways said: "May I say that my actions, along with others on the evening of that fateful night, have brought a huge shame on Aslef.

"I also believe, rightly, that we also brought Aslef into disrepute."

The internal report into the fracas at the private party said the union was "highly factionalised" and urged members to stamp out what it called a "self-destructive culture".

The document said Mr Samways had become verbally aggressive with staff, particularly with one woman, Julie Atkinson.

I made a mistake, and like all human beings, we are all capable of making mistakes Martin Samways

New Aslef general secretary Shaun Brady had attempted to physically remove his colleague when the woman was hit in the mouth by the president.

The report, which was produced by an independent three-member panel, did not conclude whether the blow was deliberate but said Mr Samways' behaviour was "wholly unacceptable".

The former president accepted the criticism of his behaviour but denied allegations he had struck Ms Atkinson.

In his statement on Thursday, he said he had made a "terrible error of judgment".

He went on: "I made a mistake, and like all human beings, we are all capable of making mistakes. However, I am not excusing my behaviour whatsoever.

"I am big enough to admit my mistakes and to try and rectify that mistake by acknowledging that I should resign my positions in the union forthwith."

However, Mr Samways maintained he had never spoken to female members of staff in the manner described in the report and dismissed the claims regarding Ms Atkinson as "absurd".

A separate report being prepared into the running of the union over the past decade is expected to be published soon.