This is a complete screen used British army uniform as seen at the end of the film, when the military invade Bexhill refugee camp.
Most important, these uniforms were part of the scene where Theo & Kee walk through the mesmerized troops, carrying Kee's child away from battle against surviving Fishes who took refuge in a block of flats… A haunting scene whose intention was to remind the audience of Moses leading his people through the Red Sea I guess.

The digital camouflage pattern was especially designed for the film. The costume department took a regular DPM (Disruptive Pattern Material), then reversed the pattern, changed the color to something urban and ended by giving it a digital look.
The L85 rifle is an airsoft model that is unable to shoot blank ammo, I guess the gun fires were added in post production.
The helmet cover, jacket, trousers, body armor, gloves, webbing and pouches were weathered in order to give the suit a worn out look.

the costume consists of :

Helmet + digital camo cover and goggles
Wireless headset
Black web scarf
Digital camo combat jacket
Digital camo body armor
Digital camo combat trousers
Black gloves
Black combat boots
Olive webbing (with pouches and casted bayonet)
L85 rifle (+ SUSAT scope and sling)

This costume is in excellent condition and was acquired directly from someone who worked on the film.