Labour’s candidate to replace the Tory MP Nadine Dorries has taken part in protests for Greenpeace, the group banned from Whitehall for climbing on Rishi Sunak’s roof, it has emerged.

Alistair Strathern, 33, is vying to turn the Mid Bedfordshire seat red in an upcoming by-election.

However, it has surfaced that he dressed as a zombie ­outside the Home Office last November as part of a stunt by Greenpeace against the new Public Order Act, which cracks down on disruptive protests.

He posed in make-up alongside his partner Megan Corton-Scott, who is a political officer for the eco group.

It has sparked fury from some Tories after activists from the group caused outcry by climbing onto the roof of the Prime Minister’s family mansion in Yorkshire last week and draping a black cloth over its facade to rail against his oil drilling expansion.

In response, Downing Street has ordered a blanket ban on government departments engaging with Greenpeace.