Thatcher at 100 The Tories and Reform battle to carry her flame

It is a glittering annual dinner in honour of the Conservative party's most successful leader and, on the 100th anniversary of Margaret Thatcher's birth, one that is bigger than ever.

- Ben Quinn

Margaret Thatcher: 'always challenging the status quo'

Yet as Tory grandees, celebrity backers and wealthy donors prepare for a gala dinner at London's Guildhall this evening, a battle for her legacy is under way between the party she once led and the insurgent threat of Reform UK.

Boris Johnson will make a keynote speech, the Guardian has been told, joined by the main speaker, Thatcher's son Mark, and guests including Joan Collins, Julian Fellowes and Jeffrey Archer.

But a notable absentee will be Kemi Badenoch, as the current Tory leader struggles to stave off the threat of extinction looming over the party Thatcher led to three consecutive election wins.

"There is a competition as to who is best to carry forward her legacy," said the event's main sponsor, Mohamed Amersi, who has donated £500,000 to the Tories in the past but, like other donors, has been backing Nigel Farage's party more recently.

"There's no doubt that she would have been sympathetic to much of what Reform are saying, though at the end of the day she was still a reluctant remainer."