A POLICE officer has said it was self preservation which made him attack a drinker who punched him in the face.

Bexleyheath Police Constable Alex Collins, aged 29, denies assault, perverting the course of justice and misconduct in a public office.

The Old Bailey heard Collins was one of several officers called to an incident outside the Zero Bar in Bexleyheath Broadway, on September 6 2003.

Tarnjit Bhandal had been to a wedding and then gone to the bar with friends Manjit Singh and Ajay Rana.

Mr Singh was drunk and was asked to leave after arguing with other customers.

He then started a row outside the bar, brandishing a chair at a group of people jeering from the opposite side of the road.

When police arrived, one of the group Steven Bibby threw a punch at Mr Singh and was detained by Police Constable Mark Burrows.

Collins then warned Mr Bhandal not to interfere or he would also be arrested.

It was alleged Collins pushed him up against a window and drew his CS canister.

Mr Bhandall then pushed Collins, but it is alleged the PC lost his temper as two other officers restrained Mr Bhandal, punching him twice in the head and body, kneeing him and pulling his hair.

Collins is also accused of persuading PC Burrows to take responsibility for Mr Bhandal's arrest, even though he saw none of the incident.

PC Burrows, who has admitted misconduct in a public office by suggesting he made the arrest, will give evidence against Collins.

The jury saw CCTV footage of the incident and Collins indicated when he thought Mr Bhandal hit him.

"I clenched my fist and I punched him. It's the self-preservation juices just let you do it," he said.

Because of the complaint against the officers, public order charges against Mr Bhandal, Mr Singh and Mr Bibby were dropped.

The trial continues.