This question was answered on 14th December 2020
Most pension avoidance scheme promoters do not break the tax rules. But where they do, HMRC will pursue them. HMRC is responsible for pension tax relief but not for the regulation of pension schemes. Regulation is the responsibility of the Pensions Regulator and the Financial Conduct Authority. HMRC works with other regulators and law enforcement agencies, through Project Bloom, to ensure a co-ordinated and joined up approach is taken to tackle pension avoidance schemes.