The chair of Reform UK, Zia Yusuf, was a member of the Conservatives until last week when party officials were approached by the Guardian. Richard Fuller, the Conservative party chair, emailed Yusuf to tell him his membership had been revoked last Friday afternoon, after the Guardian asked the party whether it was still active. That means Yusuf remained a paid-up Tory member despite announcing he had donated a six-figure sum to Nigel Farage’s party in June, and then being unveiled as chair of Reform UK in July. The Conservative party did not cancel his membership even after Yusuf embarked on a series of broadcast interviews attacking Rishi Sunak and the government, and urging voters to make Farage prime minister. He told GB News in June that the Conservatives were “so divided that I simply don’t see how they can govern effectively”. Addressing a Reform UK rally in Birmingham in June, Yusuf accused the Conservatives of having “lost control of our borders” and having “no coherent immigration policy”. Within two weeks he had been made chair of Reform UK, replacing Richard Tice. Had the Guardian not alerted the Conservatives to it, Yusuf’s membership might have continued indefinitely, allowing him to vote in the Tory leadership contest in November. It raises questions over whether other senior Reform UK figures are current Conservative party members. Yusuf told the Guardian in an interview last week that he had voted Conservative for most of his adult life. “They make it quite hard to actually cancel your membership. For all I know I might still have a direct debit with them,” he said. He said he had stopped supporting the Conservatives because of Boris Johnson, suggesting that his government’s policies were so leftwing they could have been former Labour leader Jeremy Corbyn’s. “My enthusiasm for the Conservatives was really extinguished after we saw the aftermath of what Boris Johnson had done … That sense of betrayal is something that I think a lot of people feel in this country about the Conservatives,” Yusuf said. “Boris had a walloping mandate, he came to power on the back of the promise that he would get Brexit done and then make the most of the opportunities that Brexit presented, and he really governed way further to the left than what he promised. If Jeremy Corbyn had come in and governed that way … that wouldn’t have been a betrayal.” Electoral Commission records show that Yusuf gave Reform UK £200,000 in June, one of the biggest donations made by an individual in the election campaign. Reform UK has been at the centre of a series of scandals. A Channel 4 investigation recorded Reform activists making racist and homophobic comments while campaigning for Farage during the election, while several of the party’s election candidates were dropped over links to far-right groups or racist comments they had made in the past. A fifth of Reform UK voters said they supported the anti-immigration riots than began after last week’s mass stabbing in Southport, according to a YouGov poll this week. A third of the party’s voters said they thought the unrest was justified, though only 7% said it was “completely justified”. Opposition to the riots was near-universal among supporters of every other party. Reform UK says it now has more than 72,000 members, up from 28,000 before Farage announced he was standing for parliament in Clacton-on-Sea. A Conservative party spokesperson said: “Zia Yusuf has had his party membership suspended. The party constitution does not permit you to be a member of the Conservative party while publicly supporting another party.”