Animal rights extremists are "thugs" threatening freedom in Britain, says the chancellor of Oxford University.
Chris Patten used his first speech as chancellor to warn that protesters using violence were undermining "a free and civilised society".
The university recently won its bid for the renewal of an injunction against animal rights activists protesting next to its new animal testing centre.
One animal rights group said Mr Patten was trying to demonise protests.
Mr Patten said: "To use violence against research at a university - against academic staff and all those in any way associated with what they do - is a serious blow against the basic liberties of a plural society.
"If we surrender over animal research, what comes next? Will there be attempts to intimidate us not to employ those who belong to a particular country or faith or ethnic group?
"Pushing back the boundaries of knowledge is one of the hallmarks of a free and civilised society."
Robert Cogswell, of Speak, said: "We are not surprised by Mr Patten's comments. He is the chancellor of Oxford University and is going to be biased.
"He's got it wrong. We are not anti-science, we just believe that using animals for research will never be the answer.
"We are looking to the future of science, beyond this out-moded method, which is simply not effective in finding cures for human diseases.
"Most protesters are law-abiding citizens and Mr Patten's speech is just another attempt to demonise the animal rights movement."
The injunction against the protesters creates a 45m exclusion zone - banning picketing, demonstrating or loitering - around the university's buildings and grounds and the property of any of the contractors.
There is also a 91m "no go" area around the homes of the university's members, employees and their families, its shareholders, its contractor employees, shareholders and their families, and anyone who visits the research laboratory.