It is a morally very awkward situation really.
The more exposure a person with extremist viewpoints gets, the more popular they seem to become. However, you cannot ban them from speaking because although they have a different viewpoint to your own, it's still a viewpoint and it's fully legal to express it.
That's one of the things that the 'incitement to hatred' law is tricky with, and indeed, it's a conversation I've had with Steve and Jim before, in how tricky it is to allow free speech but to curtail hate speech at the same time.
I think that they should allow him, although he's going to need a fair bit of security, so if there's a reason to deny his request it would be the inordinate amount of security that would be needed to protect him from protesters and/or people looking to kill him.
I would love to say that it would be easy to let him speak and show himself up for the idiot that he is, but history has taught us that if a person is smart enough, using hatred and fear against other races or religions is a pretty easy way to get people to follow you.
Catch-22, the cost of free speech I guess, people can say stupid things as well as smart things.
