Richard Tice has appeared to issue an invitation to Lee Anderson to join Reform UK.
The leader of the rebranded Brexit Party said the Ashfield MP, who is at the centre of a row over comments about Sadiq Khan, has his number.
Mr Anderson lost the Tory whip over the weekend after refusing to apologise for saying “Islamists” had “got control” of the London Mayor.
Mr Tice said: “Lee Anderson may have been clumsy in his precise choice of words, but his sentiments are supported by millions of British citizens, including myself. Never has Westminster and the craven left-leaning establishment been so out of touch with ordinary people.
“I do not and will not give a running commentary on any discussions I have with any MPs, but those MPs have my number.”
Mr Tice hit out at pro-Palestine protests which have been regularly taking place in London in the wake of Hamas’s attack on Israel on October 7.
The businessman said: “The truth is that Lee speaks for millions of people who are appalled by what is happening to our country. Between them, this gutless Government and the Mayor of London appear to have lost control of our streets.
“The projecting of a vile antisemitic slogan on our Houses of Parliament last week is a shocking illustration of the breakdown of law and order.
“In his role as London’s Police and Crime Commissioner, Sadiq Khan is responsible for London’s security. Along with Sir Mark Rowley, he has totally failed in that capacity. Week in, week out, he and the police have allowed pro-Hamas, hate-filled antisemitic marches to continue.
“I first called for these ugly demonstrations to be banned on October 11, having seen first-hand the awful behaviour on the first march on October 9. It took place before Israel had even responded to the horrors of October 7.
“Fast forward to today and – thanks to woefully weak leadership on the part of our authorities – extreme Islamists are creating a sense of fear and intimidation in our capital. With every failure to crack down on their behaviour, they become emboldened.
“The Jewish community is scared; Londoners are scared; MPs are scared; the Speaker is scared. Even the police appear too scared to do what they are supposed to maintain the peace in our capital: arrest those who demonstrably break the law.”
Mr Anderson today admitted his original remarks on GB News were “clumsy”.
But the former Tory deputy chairman added: “If you are wrong, apologising is not a sign of weakness but a sign of strength.
“But when you think you are right you should never apologise because to do so would be a sign of weakness.”
In a fresh attack on Mr Khan, he said: “Hundreds of people had been arrested for racist abuse on these marches and we barely hear a peep from the mayor.
“If these marches were about something less fashionable, Sadiq Khan would have been the first to call for them to be cancelled. It’s double standards for political benefit.”
Prime Minister Rishi Sunak said Mr Anderson had been deprived of the Tory whip because his “choice of words wasn’t acceptable, it was wrong”.
