Nigel Farage will be headlining at an American conservative summit brought to the UK by Liz Truss next month alongside hard-right speakers, despite his party previously suggesting he would be “steering clear”.

The Reform UK leader has announced he will speak in July at the Conservative Political Action Conference (CPAC), which claims it wants to “save Britain, save the west”.

He will be one of the main speakers at the event, alongside figures such as the US rightwing influencer Jack Posobiec, who supports “remigration” and previously promoted the fabricated “Pizzagate” conspiracy theory smearing prominent Democrats as paedophiles.

At US CPAC in 2024, Posobiec claimed: “Welcome to the end of democracy. We are here to overthrow it completely. We didn’t get all the way there on January 6, but we will endeavour to get rid of it.” He later said he just wanted to end the Democrats’ version of democracy.

Other political figures due to speak at the British event include the former Conservative cabinet minister Jacob Rees-Mogg, who had also previously indicated he would not take part. He is understood to have changed his mind because he did not like to see Truss being politically shunned.

Farage’s decision to take part comes against a backdrop of Reform UK losing support to the right in the Makerfield byelection, where Rupert Lowe’s Restore Britain is gaining a presence.

The Reform UK leader has also been under pressure over his decision to take a £5m gift from the crypto billionaire Christopher Harborne before the election, which was not declared. It is now under investigation by the standards commissioner, and Farage has not been giving his usual press conferences for some weeks since the Guardian revealed the existence of the gift.

Reform sources told the Guardian in March that the party would be “steering clear” of the CPAC event, but Farage later said he had not confirmed either way. Asked by the Guardian after a press conference why he was not attending, he replied: “I haven’t said I will or won’t.”

Tickets for the CPAC conference, which will take place in London on 16-18 July, range from £100 to £10,000 for those who want access to a VIP lounge, premium seating, drinks events and a Winston Churchill gala dinner.

Truss, who was briefly prime minister in 2022 before resigning over her handling of the economy, was appointed to run the British version of CPAC earlier this year. She has moved further to the right but has not been welcomed into Reform UK, largely due to concerns about public anger over the impact of her mini-budget on mortgage rates.

The CPAC in the US is a major gathering of conservatives, previously attended by Donald Trump and Farage, which the organisers hope to replicate in the UK.

In a recent video to promote the event, CPAC GB claims “our history, our identity, is under threat”, before flashing the word “refugees” on to the screen and someone wrapped in the Pride flag.

Matt Schlapp, the US chair of CPAC and a lobbyist with ties to the Donald Trump administration, will also give a speech, as well as the YouTuber Peter McCormack, and the Reform UK activist and candidate Matt Goodwin. The line-up also includes Toby Young, a Conservative peer and founder of the Free Speech Union, and Lucy Connolly, who was imprisoned for calling for followers on X to set fire to asylum hotels, and now describes herself as a free speech campaigner.

The event appears to be part of a trend for well-funded major summits of rightwingers in London, with the Alliance for Responsible Citizenship due to have an event in June. Farage has not confirmed whether he will attend ARC but the Conservative leader, Kemi Badenoch, is on the programme.

Last year’s ARC event featured Farage and Jordan Peterson. Its backers include Paul Marshall, one of the owners of GB News, and Legatum, a private investment company.