Boris Johnson is among parliamentary candidates being targeted by the National Campaign Against Insurance Premium Tax.
The Yorkshire-based protest group has written to all MPs and parliamentary candidates seeking their support against further increases in the tax on premiums.
Spectator editor Johnson was last week adopted by the Conservative's to contest Michael Heseltine's seat when he steps down at the next election.
The NCAIPT claims to have secured the support of 150 MPs, including Ken Livingstone and William Hague.
