gainful workmeans— (a) work from which the person concerned gains the whole or a substantial part of the person’s income (ignoring any income received from investments, trusts or other sources not related to work), being work— (a) under a contract of employment, (b) as the holder of an office, or (c) as a self-employed person engaged in a business or profession;
the Principal Regulationsmeans the Parliamentary Pensions (Consolidation and Amendment) Regulations 1993.