Sounds like the usual ill-informed parliamentary debate on defence issues, where the MP can't be bothered to find out the facts, or thinks he knows what he's talking about without checking. He probably just means going outside of a defended location on the ground.
Patrolling 'the streets' (or any other part of Iraq or Afghanistan) is fundamentally soldier (generic) business, ie, for those who are trained for the purpose. Anyone else attempting it is asking for trouble and would probably be a liability in a contact.