A man who attacked the boss of an animal research firm with a wooden stave has been jailed for three years.

David Blenkinsop, 34, of Broadhurst Manor Road, Horsted Keynes, pleaded guilty to unlawful wounding.

Judge Neil McKittrick described it as a wicked act against a defenceless man.

Brian Cass, 53, the managing director of Huntingdon Life Sciences in Cambridgeshire, suffered a 7cm head wound during the attack outside his home in February, Peterborough Crown Court heard.

Karim Khalil, prosecuting, said Blenkinsop was one of three people who attacked Mr Cass with staves and pickaxe handles.

Mr Khalil said Mr Cass had lived in fear of being attacked when animal rights activists launched a concerted campaign against the company in December 1999.

He said: "He has lived in fear of violence against himself since this campaign began."

A neighbour who chased the attackers was sprayed in the face with CS gas.

The pickaxe handles were bought from a DIY store in Oxford and it was DNA from these and clothes, found a few days later, that led to the arrest of Blenkinsop.

Ian Macdonald, defending, said Blenkinsop, who had previous convictions for violence and assault, had committed offences for his animal rights beliefs.

He added: "He was, and remains, appalled at the suffering of animals at HLS. He deeply regrets his part in this attack and now realises peaceful protest is the only way forward."

Judge Neil McKittrick, told Blenkinsop it was a "wicked act that did no good at all".

He said: "This had nothing to do with legitimate and peaceful protest."

John Hughes, of Kenilworth Road, Hastings, who was facing a charge of conspiring to cause grievous bodily harm to Mr Cass, had his case dismissed.

Animal rights campaigners have mounted an increasingly determined campaign against Huntingdon Life Science because of its research work, which requires animal experimentation.

Blenkinsop was originally arrested in a raid on a sanctuary run by television writer and animal welfare campaigner Carla Lane.

The creator of TV sitcoms Butterflies and The Liver Birds stressed he was not employed at the premises in Horsted Keynes but visited his girlfriend who is veterinary nurse there.

Ms Lane, who has previously been involved in protests against the exportation of calves to Europe, said: "It's sad for anyone to be violent for any reason but I understand their anger and their passion.

"That doesn't mean I condone it. If David was here I would say, 'David, you are a fool.' But he is one of the nicest people I know and he is not a violent man."