It seems many are unfamiliar with the history of over 130 terrorist incidents in London perpetrated by Irish nationalists. Most of these took place as part of its 1975–1998 campaign during "the Troubles" in Northern Ireland beginning in 1970 and continuing up to 2001.

And the last British MP killed?  Labour MP Jo Cox by a Neo-Nazi far-right white supremacist.  That  incident was the first killing of a sitting British MP since the death of Conservative MP Ian Gow, who was murdered in a Provisional Irish Republican Army terrorist attack in 1990.

Neo-Nazi David Copeland (aka the London Nail Bomber) bombed Black British, South Asian and LGBT populations on a 13-day campaign In April 1999 in the hope of triggering a UK race war -  3 died and more than 140 were injured in the attacks.  His inspiration was The Turner Diaries, a novel referred to as the  "bible of the racist right" by American white supremacist William Luther Pierce.  

Terrorists are not limited to radical Islamists.