Question to the Home Office:

To ask the Secretary of State for the Home Department, with reference to her Department’s publication entitled Annual statistics of scientific procedures on living animals, Great Britain 2024, published on 23 October 2025, what assessment she has made of the potential implications for her policies of the increase in the number of (a) marmosets and tamarins and (b) rhesus monkeys used for the first time in scientific procedures from 2023 to 2024.

The requirements for regulatory testing are set by regulators such as the Medicines and Healthcare Products Regulatory Agency, which regulates medicines, medical devices and blood components for transfusion in the UK.

The use of non-human primates continues to represent a very small proportion of the total number of procedures carried out in Great Britain, accounting for approximately 0.1% of all experimental procedures in 2024. The total number of procedures using non-human primates, and the total number of non-human primates used decreased in 2024 compared to 2023. Non-human primates are required by regulatory authorities for use in their assessments of whether potential medicines and other therapeutics are to be considered safe for human use. Non-human primates are also used for the safety assessment of novel pharmaceuticals in cases where they are the most appropriate and scientifically justified species.

Non-human primates are classed as specially protected species, and their use is permitted only under exceptional circumstances.

The Animals (Scientific Procedures) Act 1986 ensures that all use of non-human primates in the UK is strictly regulated and licences that authorise testing on non-human primates are only granted where there is robust scientific justification and no viable alternative. Each project licence application is subject to a rigorous harm-benefit analysis, and the welfare of the animals is a primary consideration at every stage.

This Government is committed to the development of non-animal alternatives and will publish a strategy by the end of this year to support the development, validation and uptake of alternatives to animal testing.