Rupert Lowe, the MP for Great Yarmouth who quit Reform UK after a bitter split with Nigel Farage, has launched a new national political party, pledging “mass deportations” and drawing quick support from figures and groups to the right of Reform.

Speaking on Sunday night at an event in Great Yarmouth, Lowe told supporters that “millions will have to go” as he set out plans for a hardline anti-immigration platform. The gathering, held in a dilapidated theatre at the end of Britannia Pier on a cold winter evening, was billed as the launch of a local “Great Yarmouth First” party but was used to announce that Lowe’s Restore Britain movement would now become a national party.

Lowe introduced five councillors who will stand under the Great Yarmouth First banner at the next Norfolk county council elections, which have been postponed. He said the local party would act as a pilot for a wider model under which Restore Britain would operate as an umbrella for similar local groups.

While Lowe’s new party is at an early stage and has yet to show electoral strength, the speed with which other hard-right figures rallied around it has heightened concerns that a splintering of the vote to the right of the Conservatives could disrupt future contests in marginal seats.

Advance UK, led by former Reform deputy leader Ben Habib and backed by the far-right activist Tommy Robinson, said it would consider a merger with Lowe’s new party. Such a tie-up could increase pressure on Reform by drawing away activists and donors as well as voters, potentially weakening Farage’s party in closely fought constituencies.

A Conservative strategist said the risk of disruption was heightened by the scale of narrow wins in the last general election, when Labour secured a large overall victory but many of its MPs were elected with majorities of around 1,000 votes. In 2024, 46 seats were won with a margin of less than 2%, the strategist noted, leaving scope for small movements on the right to have an outsized impact.

Lowe and Habib have both built sizeable online profiles and have been heavily amplified on X, where Elon Musk has signalled support for Lowe. Musk retweeted Lowe on Saturday with the message: “Join Rupert Lowe in Restore Britain, because he is the only one who will actually do it!”

Musk has previously funded Robinson’s legal bills, according to reporting, and has increasingly distanced himself from Farage while boosting Lowe’s posts. The online support has been accompanied by the rapid alignment of a cohort of young rightwing would-be influencers, some of whom promote a more exclusive and ethnically nationalistic view of British identity.

Among those attending Lowe’s Great Yarmouth launch was Lucy White, an activist and occasional GB News contributor who has been accused of racist tweets. Steve Laws, described by opponents as an “ethnonationalist” influencer, posted on X: “Rupert Lowe is our leader. GET IN LINE.”

Other prominent names have also sent approving signals, including the businessman Duncan Bannatyne and the actor John Cleese, though neither has announced any formal role.

Habib, meanwhile, has sought to position Advance UK as the heir to what he calls Reform’s original mission, arguing that Farage has moderated the party’s approach and tightened central control. “Reform are vacating the part of the political spectrum on which it was founded. We’re the old Reform, and Reform is becoming the Tories 2.0,” Habib said ahead of Advance’s first policy launch at the Emmanuel Centre, a Westminster venue let out by an evangelical church.

Habib, a former Brexit party MEP, said he had put £100,000 into Advance UK and that the party had raised a further £600,000 from other sources. He said some supporters were joining because they were “fed up with the way Reform is run”, while others believed Farage was “changing the message”. He also criticised Farage over links to global elite gatherings, saying Reform’s original manifesto rejected the World Economic Forum but that Farage had accepted money from an Iranian billionaire to attend Davos.

Advance UK has also tried to cultivate a street-protest presence. Its flags were prominent among thousands who marched through Crowborough, East Sussex, last month against the use of a former military base to house asylum seekers. Some flags were handed out to people who were unaware of the group, according to organisers and witnesses.

An early test of Advance UK’s support is expected in the Gorton and Denton byelection later this month, where the party is standing Nick Buckley, who received an MBE for charity work but has since become known for inflammatory language on race and Islam.

Lowe’s launch comes as Reform attempts to consolidate its gains after its 2024 breakthrough, which included winning Great Yarmouth. The town is one of several English coastal communities with high levels of deprivation where Reform built support, presenting itself as a challenger to both Labour and the Conservatives.

Reform sources said they expected to hold Great Yarmouth at the next general election, saying: “We won it last time and we will win again.” But Lowe’s personal following among some Reform members and activists has made him a focal point for discontent on the party’s right flank.

Since his departure from Reform, Lowe has continued to attract attention, including through a self-styled “inquiry” into the grooming gangs scandal that drew the involvement of Conservative MPs including Nick Timothy, Esther McVey and Gavin Williamson.

At the Great Yarmouth event, activists and former Reform supporters travelled from across the country, including from Scotland. Among them was Maria Bowtell, an East Riding of Yorkshire councillor and single mother who was previously regarded as a rising star within Reform and who attended with her young son.

Bowtell said she felt Reform no longer offered the kind of change it once promised. “Reform used to stand for something hopeful but it’s clear they won’t really change anything, plus people like me just weren’t supported,” she said. “I went on Woman’s Hour and was hung out to dry. I’m attracted now to the idea of independents getting together.”

For now, Lowe’s party remains untested in elections and faces the structural difficulties that have historically hampered new political startups under the first-past-the-post system. But with Advance UK signalling openness to a merger and with high-profile online backing helping to drive attention, the emergence of Restore Britain has added fresh volatility to an already fractured space on the right of British politics.

Attention is expected to focus in the coming weeks on whether any formal deal is struck between Restore Britain and Advance UK, how both parties perform in the Gorton and Denton byelection, and whether defections from Reform accelerate ahead of delayed local elections in Norfolk.