Advocacy Groups are groups of members who share a religion (eg Muslim) or belief (eg a belief in climate change) that is legally protected, or should be because it is consistent with the Equality Act (2010) definition. Alternatively, they may organise around any single aspect of any of the other protected characteristics - for example, an Advocacy Group for older women. They choose to come together and mobilise in order to influence party policy, and there is no limit on the number of advocacy groups that may form.

Advocacy groups are not endorsed by the party, and that independence also means both the requirements and benefits are looser than for caucuses.