The injured policeman later needed hospital treatment and was given morphine to dull the pain.

Magistrates heard how Daniel Keenan was one of a group of 80 people involved in a late night disturbance outside The King Oswy pub, in King Oswy Drive, Hartlepool.

The 24-year-old admitted causing actual bodily harm and being drunk and disorderly when he appeared at Hartlepool Magistrates' Court.

Prosecutor Stephen Hill said: "Police were called to the King Oswy public house because there was some sort of large scale disturbance going on."

When the officers got there around 11.35pm they reported how "tensions appeared to be high".

Keenan, of Dowson Road, Hartlepool, was in a group close to the exit, shouting and swearing and refusing to leave.

Mr Hill said Keenan was described by police as "drunk, unsteady on his feet and his eyes were glazed".

The court heard Keenan repeatedly refused to leave and had to be pushed out of the premises and handcuffed. His girlfriend started to act aggressively to police as Keenan also became more aggressive, the court was told.

In a statement the officer said: "When he realised that he was not going to get away, he pushed violently towards me with his right arm."

Paramedics at the scene confirmed the officer's right shoulder was dislocated and he was taken to the University Hospital of Hartlepool, where he was given morphine.

In interview Keenan said he had nine or ten pints but denied refusing to move on, claiming he was trying to leave the pub.

Mr Hill said that Keenan accepted his behaviour was disorderly and while he could not understand how the officer gained his injury, he did not dispute that he had contributed to it.

Of the overall disturbance, which occurred on March 23, Neil Taylor, mitigating, said: "Daniel Keenan became involved in an incident he did not start and his girlfriend was embroiled in."

Mr Taylor said Keenan accepts he had too much to drink and "did not responded appropriately when he was asked to move on".

He said unemployed Keenan, who has not been in trouble for over five years and has no history of violence, had tried to "yank himself away" in a bid to assist his distressed girlfriend.

Magistrates ordered a pre-sentence report and gave Keenan conditional bail until he reappears at court on May 15.