Kassam remarked on the campaign against Trump by the political figures ahead of his anticipated visit: "Sadiq Khan as the mayor of London has really been tubthumping, trying to get President Trump not to attend".
Pro-Trump protesters attempted to interrupt a speech by London Mayor Sadiq Khan and have called for his arrest, Sky News reported Saturday. "But they told us Sadiq Khan has no right to be Mayor of London, referencing his religion".
The protest comes just one day after Khan - who has been an outspoken critic of the American president - issued a statement about Trump canceling his London visit over an inaccurate claim of President Obama selling the former US embassy "for peanuts".
Audience members started to heckle and slow clap as security officers appeared.
"Ladies and gentlemen, we're here today to make a non-violent, peaceful citizen's arrest", the protesters declared whilst holding up an American flag, only minutes after Khan, London's first Muslim mayor, was introduced on stage to deliver his keynote speech at the left-wing think tank Fabian Society conference.
However their attempts to eject those responsible for the disruption were initially met with aversion from the protesters, one of whom could be heard saying: "We stand under Common Law jurisdiction".
Khan on Friday had said that President Donald Trump had "got the message" that he was "not welcome in London" after the president canceled a planned state visit.
"We're not leaving, we've paid for a ticket".
Mr Trump recently used the words "stable" and "genius" to describe himself.
The demonstrator also accused the Fabian Society of "subverting" the constitution.
The U.S. president confirmed on Twitter late Thursday that he would not visit the U.K.to open the new U.S. embassy building in south London.