Campaigners dressed as monkeys in pinstripe suits were at Downing Street yesterday to hand in a petition calling for a total ban on primate testing in Britain.
Carrying briefcases and umbrellas, and wearing bowler hats on top of huge monkey heads, they delivered 163,000 signatures to Tony Blair.
The cumbersome outfits proved too much of a security risk and police made the protesters wait outside the gates to Downing St, leaving the task of delivering boxes of signatures to the Liberal Democrat MP Norman Baker.
"It is profoundly sad in the 21st century that we are still conducting these experiments on highly intelligent creatures," said Mr Baker, MP for Lewes, east Sussex. "There are alternatives that are both more humane and reliable. You can't extrapolate from experiments on primates to humans, it is simply bad science."
The Next of Kin campaign was organised by the British Union for the Abolition of Vivisection, which claims many primate experiments are liable to cause "pain, suffering, distress or lasting harm".
Home Office figures for 2003 show that more than 3,000 non-human primates were used in experiments in the UK. Studies suggest some toxicology procedures lead to nausea, diarrhoea, vomiting, weight loss, lethargy, unsteady gait and death.