The Last Seven (2011) on Netflix

Plot summary

After a catastrophic event, London stands empty, and William Blake comes to on one of its streets, face down and alone, with no memory of his name or how he got there. He wanders the silent city: no cars, no buses, no sign of life, as if its whole population has vanished. He meets six strangers who are also alive, and the seven work out that they may be the only survivors. One of them, Sergeant Jack Mason, is a uniformed soldier carrying a weapon, and he takes control to restore some order. Flashbacks trouble the group, recalling situations they have already lived through.