The British Union for the Abolition of Vivisection has launched proceedings against David Blunkett for failing to regulate experiments.
Under UK law, the Home Secretary is responsible for ensuring that the suffering caused by such experiments is evaluated before they are authorised.
But BUAV argues that the Government deliberately hides the gravity of experiments on primate brains by classifying them under a category for lower suffering levels.
"The Government plays down the suffering that lab animals experience," said Wendy Higgins, campaigns director at the BUAV.
The judicial review is the second legal case brought against the Government by animal-rights charities this year. The Home Office has until 26 January to respond to the legal challenge.