Why ban Hezbollah?

I don 't like organisations being banned and see little justification for it ever. I do not know much about the political wing of Hezbollah, except it is backed by Iran and wins many votes and seats in the Lebanon. I have not seen any evidence that its political wing is any threat to Britain but the British Home Secretary has decided that it will be banned.

Sinn Fein the political wing of the IRA was not banned even though the IRA was murdering British people.

Tony Blair made terms with the IRA terrorists which I regret. His hugely rich Institute has been lobbied hard and successfully for the UK to ban Hezbollah and was paid $12 million by Iran’s enemy, the Saudi monarchy. 

Hezbollah have been fighting against ISIS and Al Qaeda in Syria, who have been fighting on the side of the so called moderate rebels backed by the Anglo-Americans.