The government on Wednesday published new guidelines for medical research companies targeted by animal rights extremists.

The documents, published in a consultation paper, provide new advice on personal safety for employees in vulnerable companies and sets out the Crown Prosecution Service position on action against animal rights protestors.

The Home Office also set out new guidance to the police to help ensure consistent and effective enforcement of the law.

Announcing the new drive, Jack Straw said: "As we have made clear, we are simply not prepared to let a small minority of criminal extremists intimidate members of the scientific community and their families, and try to prevent essential medical research."

He said that the government would not allow extremists to threaten those involved in research.

"We fully support every individual's right to peaceful protest, but we will not tolerate violence, threats and harassment. This type of research saves lives and treats the illnesses of millions of people - the people conducting it must be able to continue this essential work," Straw said.

Bill Fullagar of the Association of the British Pharmaceutical Industry welcomed the government's announcement.

"The pharmaceutical industry is heartened by the government's determination to protect researchers, their families and the organisations for which they work. It is crucial that the new measures are used effectively if companies are to continue to research and develop new medicines in Britain," he said.