CNN
Blair, speaking nearly a month after deadly bombings on London's transit system, said Friday the UK's human rights act would be amended if necessary to counter Islamic extremists.
Keep them in Britain, where the moderates could police the extremists themselves. Try and have calming effect on the extremists. But that probably wouldn't work. Easier to keep tabs on the extremists this way.
Or by forcing them out of the UK, you move them to hotbeds of extremism, where they are fed nothing but propoganda and hate. It definately would be harder for the British to keep tabs on them. And would require more stringent screening of people comming into the country.
Keep your friends close, and your enemies closer.