Tommy Robinson has been appointed as an adviser to Ukip leader Gerard Batten.
The controversial activist – real name Stephen Yaxley-Lennon – will advise Mr Batten on rape gangs and prison reform.
Batten said the English Defence League founder had “great knowledge” about the subjects.
Robinson was jailed for 13 months for contempt of court in relation to his activities filming people involved in a grooming case.
The sentence was later quashed and the case has been referred to the Attorney General.
Batten said: “I have appointed Tommy Robinson to be a personal special adviser on two subjects which he has great knowledge.
“It is not necessary for him to be a party member in order to assist me in this role.
“I am looking forward to working with him.”
Robinson has had a series of run-ins with the law.
Years before he founded the EDL in 2009, Robinson was convicted of an assault, reportedly on an off-duty police officer.
Robinson was also imprisoned in 2013 for using someone else’s passport to travel to the US.
Other convictions include drugs and public order offences and he was jailed in 2014 for 18 months for mortgage fraud.
He said that “going to prison was the best thing that ever happened to me” after the passport conviction.