Tim Shipman and James Heale

When Zia Yusuf first walked into the headquarters of Reform UK, he gestured at the empty room and asked: ‘Where’s the office?’ Ed Sumner, the party’s director of communications, replied: ‘This is it. It’s empty. This is the party.’ That was not even two years ago. Since then, Nigel Farage and Yusuf have built a party from scratch and expect to be the biggest winners in the local elections on 7 May. With more than 270,000 members, their grassroots base is the largest in Britain, bigger than both Labour and the Tories. ‘I would argue no party has built political infrastructure and established itself more quickly in British history than Reform,’ Yusuf says.

Those pondering why Robert Jenrick defected to Reform UK have focused on the political momentum of Nigel Farage or the performance of Kemi Badenoch, but the key conversation was the one he had with his father on Boxing Day. ‘He’s a very straight talker,’ Jenrick explains when we meet at Reform’s headquarters on Tuesday afternoon. ‘He said, “If you weren’t in politics and there was a general election to-morrow, which party would you vote for?” I said, “Reform.” He said, “If you weren’t in politics, weren’t a candidate, had no particular loyalty, who would you want to be prime minister if the choice was Keir Starmer, Kemi Badenoch and Nigel Farage?” I said, “Nigel Farage.” He said, “Well, be honest with yourself and become a Reform MP.