Animal rights campaigners have been given the go-ahead to challenge the legality of vivisection experiments at Cambridge University.
Is it morally right to test drugs on animals?
On Tuesday, High Court judge Mr Justice Stanley Burnton, gave the British Union for the Abolition of Vivisection (BUAV) the go-ahead to seek a judicial review.
BUAV claims secret documents reveal laws intended to protect lab animals are not being properly enforced.
But the terms of the review are stricter than BUAV had hoped for.
In February BUAV claimed that during a 10-month undercover investigation officials discovered monkeys which had had the tops of their skulls sawn off.
BUAV said its finding contradicts the view that animals are protected under the Animals (Scientific Procedures) Act 1986.
The Government asked the then chief inspector of animals, Dr Jon Richmond, to review the licences.
The chief inspector rejected BUAV claims that the project licences should not have been granted, or that stricter "severity limits" should have been enforced to ensure the monkeys suffered the least amount of pain and suffering.
One challenge rejected
On Tuesday, Mr Justice Burnton said there was evidence that it was arguable that the chief inspector may have erred when he concluded that the severity limits had been correctly applied.
But the issue before the court was whether the Home Secretary acted irrationally and unlawfully when he accepted the chief inspector's conclusions.
Rejecting that challenge, the judge said it was not easy for a claimant to show a perverse decision had been made.
But the judge gave the BUAV permission to seek a declaration that the Home Secretary was under a duty to weigh the likely death of an animal against the benefit of a research programme when considering whether a licence for experiments should be granted.
The Home Secretary had accepted that the "likely suffering" of any animal was an adverse effect to be taken into consideration, but not death of itself, absent of any pain or suffering.
The High Court will also be asked at the full application for judicial review to investigate the rules and guidance on restricting food and water for laboratory animals.
In a statement, a Cambridge University spokesman said a Home Office inspection report in 2003 had confirmed there was no evidence to support the BUAV's allegations on non-human primate research.
"In February 2003, we welcomed the Home Office Chief Inspector's report called 'Aspects of non-human primate research at Cambridge University' as confirmation that there was no evidence to support the allegations made by the BUAV," said the statement.
"The report confirmed that the welfare of animals used in research at Cambridge is of the utmost importance, that good science and good animal welfare go hand in hand, and that the value and importance of the science here should be acknowledged."