The Royal Mail boss at the centre of the Oxford postal dispute remains defiant and unrepentant about the company's actions.

Area general manager Michael Stockdale told the Oxford Mail that it was impossible to carry out a proper investigation into the claims of bullying and harassment by a group of workers until all staff had gone back to their jobs.

He said: "We want to investigate how they feel but there are policies and procedures that need to be adhered to. We cannot deal with conjecture -- we need to investigate properly and thoroughly.

"If people are unsatisfied with those there are other means. We have hierarchies that serve to register dissatisfaction but one of those is not unofficial strike action."

Mr Stockdale said he was aware of three incidents involving clashes between rival sets of workers that sparked the dispute.

Asked whether the procedures covered alleged attacks against staff outside work, Mr Stockdale said such information had been passed on to the police.

He added: "What we have tried to demonstrate to the union is that compared to other mail centres, Oxford is no different to anywhere else. The issue really surrounds the fact that we are now undergoing the fifth outbreak of unofficial action in six months.

"It is unacceptable, unlawful and not the way we want to do business. It is also unfair on our customers.

"We cannot continue to have a cycle of uncertainty and the constant threat of industrial action hanging over us.

"It is not appropriate for the people of Oxfordshire. We are committed to people doing this the proper way in the future."

Mr Stockdale said this was why the punishment clauses had been introduced in the proposal for the return to work which was rejected by the strikers on Monday.

While it was agreed to separate and reallocate the group at the centre of the allegations of bullying and harassment, staff would have been docked up to two weeks' overtime for taking strike action. A return to work was rejected unanimously on that basis.

As a result, the group at the centre of the allegations is continuing to work as a team at the mail centre on overtime. Striking staff complained they had been bullied out of their overtime by the group. Mr Stockdale said: "We are not trying to be difficult about anything -- we are trying to fix the problem for our customers and get the issues exposed. To do that we need professionalism in our industrial relations."