Tomorrow night Mark Westcott will be settled in front of his TV with a pizza to feast his eyes on the sixth and final episode of adventurer Bear Gryll’s celebrity jungle survival show – which he directed.

Hackney Gazette: Jamelia, Laurence Fox, Emilia Fox, Tom Rosenthal, Bear Grylls, Vogue Williams, Mike Tindall, Dame Kelly Holmes and Max George. Photo (C)bettyJamelia, Laurence Fox, Emilia Fox, Tom Rosenthal, Bear Grylls, Vogue Williams, Mike Tindall, Dame Kelly Holmes and Max George. Photo (C)betty (Image: (C)betty / Mark Johnson)

Just three contestants remain out of the initial eight on ITV’s Mission Survive, which has seen them trekking for 12 days through the Costa Rican rainforest, proving their mettle eating live scorpions, drinking their own wee and crossing a 200 ft deep ravine on a rope.

Mark, who lives off Upper Clapton Road, had to endure some of the tasks himself – including the Tyrolean traverse - when the production team went out for a recce two weeks before the celebrities flew in.

The idea was to give the camera team a chance to see how the celebrities might react so they could capture the best facial expressions and the maximum physical effort.

“When we first saw the Tyrolean there weren’t too many of us who wanted to get too close to the edge for a better look,” he said.

Hackney Gazette: Dame Kelly Holmes, Mike Tindall and Vogue WIlliams in Bear Grylls' Mission Survive. Photo (C) bettyDame Kelly Holmes, Mike Tindall and Vogue WIlliams in Bear Grylls' Mission Survive. Photo (C) betty (Image: ?betty)

“To see it’s as much of an ordeal for Mike Tyndall and Kelly Holmes made me feel better about myself, I can tell you.”

With the constant threat of necrotic venom from the well-camouflaged Lance de Fer snake, the dangers of fast-flowing water, and the bites of sand flies which can carry dengue fever, the environment was harsh.

Mark, who directed Bear on his first TV appearance a decade ago, Escape to the Legion, said: “They wouldn’t have been challenged if it wasn’t, you are guaranteeing as much as you can that everyone will come back, but it’s harsh.

“For all of us the snakes were always at the back of our minds, we knew we could get people to medical cover quickly, but it doesn’t take away from the fact it was dangerous.

“There’s always a danger of them injuring themselves through recklessness, accident or fatigue, in every episode we pretty much drowned Dame Kelly Holmes – not intentionally, I hasten to add.

“Kelly has a fear of water and it’s the measure of her that she can go through what is for her intense trauma and then be right as rain in about two hours.

“The whole series was full of near misses and if people want to see more they should watch the finale, it’s edge of your seat stuff,” enthused Mark.

In it Bear will choose the winner out of rugby player Mike Tindall, Olympic athlete Dame Kelly Holmes and DJ and model Vogue Williams.

“It’s who has been cheerful, strong and who he would trust with his back and the lives of his kids, parents – it’s a big honour for the person that won it,” explained Mark. “One of the key qualities that Bear was looking for was an ability to smile, even when it’s really bad, you’ve got to smile and make other people smile, that counts for a great deal.”

The show airs Friday April 3 on ITV at 9pm.