The cleric from south London whose name has dominated the mayoral election campaign says he wishes he could sue the Prime Minister.
Suliman Gani was accused in Parliament by David Cameron of being a supporter of Islamic State.
Speaking to ITV News London, Mr Gani strongly denied the allegation but accepted he is unable to launch a libel case because of rules which safeguard MPs' freedom of speech.
I'm really, really upset. I'm deeply shocked - I am gobsmacked. Why am I singled out given that I have a track record on showing peaceful co-existence? I have been working, engaging with all parliamentarians, cross party parliamentarians. Why am I being singled out to be labelled by Zac Goldsmith to be the most repellant figure in the UK?
On Islamic State, Suliman Gani added:
I do not [support Islamic State] and I categorically state that if the Prime Minister had to say those very same words outside parliament I would sue him. I have categorically condemned Islamic State.
Watch the interview in full below