Apology or courts: Imam accused of IS support responds
Suliman Gani - who described the ordeal as "a smear on my good name" - has promised to set the record straight via the legal system unless he receives an apology.
The otherwise little-known Muslim community leader unexpectedly made headline news this week when he was accused of being a sympathiser with the Syria and Iraq-based extremist group by the British TV presenter and the prime minister.
David Cameron was branded a racist after he accused a Labour Party London mayoral candidate - Sadiq Khan - of associating with Gani, earlier this week.
During a parliamentary debate, Cameron accused Khan - himself a Muslim and MP - of appearing at several events alongside the imam who "supports IS".
"If we are going to condemn not just violent extremism but also the extremism that seeks to justify violence in any way, it is very important that we do not back these people and we do not appear on platforms with them," Cameron told the House of Commons. He added that he is "concerned" about Khan.
The remarks were met with outbursts by Labour MPs who shouted "racist" at Cameron while Labour party leader Jeremy Corbyn described them as "disgraceful".
Khan accused the Conservatives of running a "nasty, dog-whistling campaign that is designed to divide London's communities".
An unverified Twitter account run by the south London imam urged Cameron to "retract his comments" and suggested "this is defamation at its highest level".
In a statement posted onto the social media platform, Ghani said he is "totally" opposed to the "so-called Islamic State" which he views as a terrorist organisation.
"As an imam and community leader, I have campaigned against the evils of IS to my fellow Muslims and to others in the community.
"This matter is now in the hands of my lawyers and I intend to take it forward through to them," he said, acknowledging Cameron's parliamentary privilege which protects him from being sued for comments made in the House of Commons.
Sadiq Khan - a former government minister and human rights lawyer - is favourite to win the 5 May mayoral election.
The outburst by the PM is likely to backfire and damage the campaign for fellow Conservative Party candidate Zak Goldsmith.
Professor Tony Travers, a politics expert at the London School of Economics (LSE), said that Khan was "clearly a modern, progressive Muslim" and that opponents risked a "backlash" by raising issues which touched on his religion.