Sadiq Khan has attempted to distance himself from extremists with whom he has been associated.
Labour's London mayoral candidate said despite having shared platforms with alleged radical clerics, he was the only candidate fit to tackle the surge of Islamist extremism in Britain.
Mr Khan said “unsavoury” figures including Louis Farrakhan, the controversial American head of the Nation of Islam, were “not my chums”.
In 2002 Mr Khan - who was a leading human rights lawyer before he became a politician - defended Farrakhan as he battled to overturn a government ban on him entering the country.
He had been denied entry for expressing racist and antisemitic views. The Board of Deputies had warned that Farrakhan – who called Hitler a “great man” – would harm race relations.
Speaking to the JC during a visit to the Community Security Trust on Wednesday, Mr Khan said: “Let me be clear. These aren’t my chums. Some of the meetings that are referred to are meetings that lasted hours and hours. I would turn up, do my spiel and then leave.”
Mr Khan said he should be judged on his record. “People who know me know that throughout my political life I have been outspoken, often at risk to personal safety and my family’s safety, on issues that matter to me, which are: tackling extremism, tackling radicalisation.”
He added: “I have never hidden the fact that I used to be a human rights lawyer. I have acted for people who are alleged of committing acts of terror. I think it is unfair to assume the cases I did as a lawyer – particularly in relation to characters who are unsavoury – are representative of the views I’ve got.
“I have never hidden the fact that I was chair of Liberty. I have never hidden the fact that I campaigned for Babar Ahmed against the US-UK extradition treaty.”
The CST briefing at the Jewish security charity in Hendon, north-west London, included discussions on safeguarding police funding to protect Jewish schools.
Mr Khan said: “We have to accept that there are some Londoners who do not subscribe to our way of life – who want to damage and divide communities. We have got to make sure we tackle that.”