Reform UK is set to make a “major” announcement on Monday morning.
Richard Tice, leader of the Nigel Farage-founded party, will give a press conference at 10.30am.
The event at a central London location will be livestreamed on social media.
It comes amid speculation that former Tory deputy chairman Lee Anderson could join the right-wing populist party.
Mr Anderson was kicked out of the Conservative Party last month after refusing to apologise for claiming that “Islamists” had “got control” of London mayor Sadiq Khan.
Mr Tice did not rule out opening the door to Mr Anderson after his suspension, in a move that would give the party its first MP.
Mr Anderson was deputy chairman of the Tory party until he resigned in January to rebel against Prime Minister Rishi Sunak’s legislation to revive his stalled plan to send asylum seekers to Rwanda.
The now-independent MP has since 2019 represented Ashfield, one of the previously Labour seats in the so-called red wall where voters switched to the Tories after Brexit to give Boris Johnson his landslide victory.
Some Tories see Reform UK as a challenger at the general election expected this year, with signs of growing support for the party.
Reform UK finished in third place in two recent by-elections, although its candidate in the Rochdale contest – former Labour MP Simon Danczuk – had a poor showing.
Mr Tice has played up the danger posed to the ruling party by Reform UK candidates and has ruled out entering any electoral pact with the Conservatives.
He has insisted he would stand candidates in every constituency, unlike in 2019 when his party – then the Brexit Party – stood down candidates to help Mr Johnson.
Arch Brexiteer Mr Farage is the honorary president of Reform UK, which is seeking to attract disillusioned 2019 Conservative voters over the issue of immigration.
Mr Farage, who founded the Brexit Party – later renamed Reform UK – in 2018, has downplayed rumours of a possible switch to the Tories.
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