Director Nick Lowles said: “We celebrate Quilliam’s efforts here, but only a complete renunciation of the violence and hatred the EDL leaders have promoted, and a turning away from the anti-Muslim rhetoric they have championed, will be enough for the many thousands who have suffered from the EDL’s ugly actions over the past three years.”
Tell Mama, a group which monitors anti-Muslim attacks, also welcomed Mr Robinson's "defection".
Director Fiyaz Mughal said: "The real question is whether Tommy Robinson has changed from just a few days ago when he was at the heart of the EDL machinery and where his messages undermined the work of anti-racist campaigners."
He urged Mr Robinson "to apologise to our nation for the millions of pounds spent on policing costs and for the tensions in communities he has caused".
Mr Robinson, whose real name is Stephen Yaxley-Lennon, and Mr Carroll are due to stand trial later this month for allegedly attempting to defy a ban on marching to the scene where soldier Lee Rigby was killed, in June.
