I seem to remember liveatc.net saying that the reason for not broadcasting feeds from UK airports is that it is illegal under UK law. I certainly hope that its not illegal to listen to broadcasts from other countries in the UK on liveatc.net otherwise I'm a lawbreaker.
My favourite is JFK Company Channels particularly in inclement weather but that probably reflects my interests.
I take it that you know about flightradar24.com so that you can see what is flying over Humberside.