The Queen rocker, Egan and TV star Bill Oddie descended on the famed London landmark to launch their Votes for Animals campaign, which urges Brits to learn about politicians' animal welfare policies before casting their vote on 7 May (15).

Ahead of the march, May wrote on, "Today I'm marching for Animals. Notice those who have no compassion for animals have none for people either."

The stars launched the drive with a talk held in a central London branch of beauty store Lush, a retailer against animal testing, and they were later joined by protesters wearing paper animal masks on the walk to the home of British politics.

The Votes for Animals drive was created by May's newly-founded Common Decency organisation, Animal Aid and League Against Cruel Sports, which boasts Egan as Vice President.