A Slough man who rammed a police car and carried out a 'ferocious' attack on a constable has failed to get his jail term cut by top judges.

Rodney Cox, of Ryvers End, Ryvers Road, Langley, was locked up for seven months at Aylesbury Crown Court in November last year.

The 26-year-old admitted criminal damage and using a vehicle without insurance or a licence.

He was acquitted of going equipped for theft, but convicted of assault with intent to resist arrest.

A police officer was looking for a Vauxhall Corsa in the Amersham area in August last year, Lord Justice Davis told London's Appeal Court today.

When he spotted the car, he illuminated the lights on his police vehicle, but Cox drove off.

He tried to reverse, but was obstructed and then rammed his car into the police vehicle.

Cox was unable to escape and the officer managed to get one handcuff on him before he 'lunged forwards' and pushed the officer onto the car bonnet.

At one point during the assault, he got the constable onto the ground with the officer landing on his knee.

Cox had a 'very poor record', with convictions for 49 crimes including assault of a constable, the court heard.

He had 'significant personal problems' and psychiatric issues, said Lord Justice Davis.

The judge who jailed him commented on the 'ferociousness' of the attack and the 'violent struggle this officer had to deal with'.

"Police officers have a very difficult job to do trying to protect the community without having to deal with your type of behaviour', he told Cox.

Lawyers for Cox today argued that his jail term was far too harsh and should be reduced.

Rather than being a 'ferocious' attack, it was just 'pushing and shoving', they argued.

But Lord Justice Davis, who was sitting with two other judges, ruled: "This sentence cannot be said to be excessive."

The Crown Court judge 'had the benefit of conducting the trial' and was 'fully entitled to find this attack to be ferocious'.

The appeal was dismissed.