Protestors will gather outside a laboratory to campaign against its use of monkeys in medical experiments.

The Anti-Vivisection Coalition will demonstrate outside the National Institute for Biological Standards, in Blanche Lane, Potters Bar on Saturday.

Campaigners from the animal rights group will wear red boiler suits and light torches to protest against experiments on monkeys and urge the biologists to free the animals.

Luke Steele, head of AVC, said: “The long history of primate suffering at NIBSC must come to an end. The protest shall be a symbol of hope for the primates held at the NIBSC that their ordeal will be soon be over.”

In its first UK protest, the coalition estimates that 100 people will take part.

The institute defended its position by saying it fully complies with stringent UK requirements for animal testing, and meets new animal welfare EU regulations.

It added: “We have done more than any other laboratory in the world to reduce the dependence on animals for medicines testing.

“Our animal work is a crucial part of the work we do to protect public health - for example to help us carry out independent safety testing of vaccines that all our children receive or in the fight to eliminate HIV.

“The animals are kept in excellent conditions and are extremely well looked after by highly trained expert staff.”