Is it a sparrow? I haven't seen a sparrow in years. London used to be full of them.

wren
Thryothorus ludovicianus
they hang out in pairs and fuss at me
that's one ounce of fierce feathers

Yes, they are quite vocal when a person is near them. I always have a pair that builds a nest on my front porch and you can tell when they're around - their sound carries far! I looked out my front window just a few moments ago and there was one of the pair looking around my porch.