Bentley, who has also appeared in Game of Thrones, will lie in a pool of fake blood wearing body paint which depicts her as a monkey in a space helmet outside the Embassy in the British capital.

She will pose beside a Russian flag emblazoned with the words "Monkeys on Mars: One Giant Leap Backwards for Mankind" and she will be surrounded by members of People for the Ethical Treatment of Animals (PETA), who are campaigning to stop the Russian space agency from sending four macaque monkeys to Mars in 2017.

Bentley says, "I was horrified when I heard about Russia's plans for the four poor monkeys... Knowing how much they would suffer if sent to space, I had to do something. I'm proud to join PETA in campaigning to stop them from being handed a death sentence."

PETA Associate Director Elisa Allen adds, "If this experiment goes forward, Russia will return to the darkest days of the Space Race - a time when primates died horrifically from suffocation, overheating and impact... PETA is calling on the Russian Federal Space Agency to put a stop to this ill-advised suicide mission and be a true pioneer in modern-day space exploration."

PETA members have also sent a letter to the Russian space agency urging them to cancel the experiment and give the monkeys to a sanctuary, and Queen rocker Brian May previously backed the animal rights organisation's drive by urging fans to sign a PETA petition.

"I'd like to do something about this. God knows what they have suffered already. Let's sign... Bri," he tweeted.