More than 500 leading UK scientists and doctors have signed a declaration pledging their support for animal testing in medical research.
The declaration, drawn by the Research Defence Society (RDS), states that a "small, but vital" part of medical research involves animals. The society says it has been signed by three Nobel laureates, 190 Fellows of the Royal Society and the Medical Royal Colleges and more than 250 academic professors.
The statement, signed over the last month, is not linked to an announcement by a Staffordshire family-run guinea pig breeding farm which announced on Tuesday that it planned to shut down after a long-running campaign of intimidation by animal rights extremists.
News of the decision to close Darley Oaks Farm in Newchurch, Staffs, prompted Lichfield MP Michael Fabricant to warn the victory for the "animal rights terrorists" could encourage other groups to target similar organisations.
The Hall family had been subjected to a six-year hate campaign by extremists, including the desecration of the grave of 82-year-old Gladys Hammond, the motherinlaw of Christopher Hall, who co-owns the farm.
The family said it hoped the decision to cease the guinea pig breeding operation by the end of the year would lead to the return of Mrs Hammond's body.
RDS executive director Dr Simon Festing said: "We are delighted to have gathered over 500 signatures from top UK academic scientists and doctors in less than one month.
"It shows the strength and depth of support for humane animal research in this country."
Professor Nancy Rothwell, vice president for research at University of Manchester and chairman of RDS, said "It's vitally important that the research community sends the message that animal research is crucial for medical progress, that it is conducted humanely, and that we work within strict regulations."
Professor Colin Blakemore, chief executive of the Medical Research Council, said: "I was involved in the original declaration 15 years ago. It is as important now as it was then to show that scientists and doctors are fully aware of the importance of animal research to science and medicine.
"Of course animals must be cared for properly and never used unless absolutely necessary. This is how we do research and it would be illegal to do it any other way."
Dr Penny Hawkins, of the RSPCA's research animals department, said the declaration merely stated that the research contributed to human and animal health.
"It does not acknowledge the pain, suffering and distress that animal experiments cause, nor does it require any positive actions by the researchers who signed it.
"The RSPCA is very disappointed that the scientific community could not come up with a more proactive statement 15 years after the original declaration."
Dr Hawkins said she would have more faith that animal welfare was of "paramount importance" if the scientists committed to curbs on primate use proposed in a recent declaration initiated by the RSPCA.
A Department of Trade and Industry spokesperson said: "Medical research is vital in ensuring that we find new and better ways to tackle diseases such as cancer, HIV/Aids, Parkinson's and Alzheimer's, that have a devastating impact on people's lives.
"The Government strictly regulates and licences the use of animals, working to ensure that the highest possible standards of animal welfare. It only licenses animal research when it is fully justified, where the benefits outweigh the costs and where there are no suitable alternatives. It is also committed to a policy of replacing, refining and reducing the use of animals through the work of the National Centre for 3 Rs."