Help to identify a bird

Could be a young Robin getting his red breast.

Thanks but it was about 50% bigger than an adult robin.

I don't think it was a young goldfinch as it had no yellow on the sides or red around the face. It was quite aggressive attacking blue tits that came near the feeder.

I wonder if it could have been a chaffinch?

could be a nuthatch
www.rspb.org.uk/.../

That's it, thanks for solving the mystery.

Interesting. I’ve read that nuthatches can be quite aggressive towards other birds but the one I have visiting my feeders just minds it’s own business, grabs some nosh and then clears off.