A motorist who zigzagged down a motorway at 80mph with a traffic policeman clinging to his car has been jailed for more than 11 years.

Joe Butler, 25, of Essex Road, Bognor, was cleared of attempting to kill PC Geoffrey Poyser but found guilty of attempting to cause grievous bodily harm with intent.

The officer suffered serious bruising to his back and legs after jumping off into the centre lane of the M11 near Stansted Airport during the incident in October last year.

Chelmsford Crown Court heard that as he clung to the open driver's door, Butler told him: "You are going to die, you bastard".

The officer has not worked since the attack and is retiring after a police career spanning more than 20 years.

Judge Ben Pearson imposed a ten-year prison term for the attack and a further 15 months after Butler admitted additional offences of handling stolen property, assault and perverting the course of justice.

After returning the guilty verdict, jurors heard Butler had a lengthy criminal record, had served prison sentences and had been disqualified from driving on five separate occasions.

Jurors were told that PC Poyser, 54, and a colleague stopped Butler, who was with his pregnant girlfriend Sarah Auld, 24, for speeding through roadworks.

Butler, who was disqualified from driving, gave the name of the owner of a stolen wallet he was carrying in the Mercedes car - not realising the wallet's owner was also disqualified.

PC Poyser said Butler punched him after being told he was being arrested on suspicion of being a disqualified driver.

Butler drove off as the police officer reached through the driver's side window of the Mercedes to grab the car keys.

The officer, who is still said to be haunted by his ordeal, clung on to the swinging open door as the car sped away.

He said: "I was in a blind panic. I became cold."

He remembered Butler overtaking traffic as he sped along.

He was eventually able to jump free when the car slowed and he tumbled on to the motorway.

Butler, who told jurors that he had accidentally pressed the accelerator, was arrested two months later.