The Government looks set to introduce a new law to protect people involved in animal testing.
The rules would make it illegal for protesters to cause a nuisance of themselves, regularly protesting outside the home of the lab workers.
Researchers welcome the plans aimed at dealing with extremists, but animal rights groups want ministers to try to find alternatives to using animals.
The law would not affect campaigners who take part in peaceful protests.
Some research staff at animal testing laboratories frequently receive hate mail and threats because of their jobs.
Many people feel very strongly about the use of animals in medical research but the government says that all testing is carried out under very strict controls.