Portsmouth south MP Mike Hancock has signed a parliamentary petition calling for an end to primate testing.
The Lib Dem MP is backing calls for the UK government to take a strong stance on the subject.
It comes as Euro MPs debate changes to the animal testing regulations across Europe for the first time in more than two decades.
They will decide if primates will continue to be used in experiments or if steps will be taken to start the move away from animal testing.
Jan Creamer, chief executive of Animal Defenders International, said: 'I am delighted that Mike Hancock has looked at the evidence and supports putting a stop to primate experiments.
'Apes and monkeys are our closest relatives in the animal kingdom, and we can clearly comprehend how these animals suffer inside laboratories.
'I urge more MPs to sign the motion and signal unequivocally to the government that it needs to strongly promote a timetable to replace all primate experiments in Europe.
'These tests can and must be replaced by reliable human-based research.'
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