Membership of Reform UK has surpassed that of the Conservatives, Nigel Farage’s party has said.

A digital counter on the Reform website showed a membership tally before lunchtime on Boxing Day ticking past the 131,680 figure declared by the Conservative Party during its leadership election earlier this year.

Mr Farage said it was a “historic moment” as he posted on X: “The youngest political party in British politics has just overtaken the oldest political party in the world.

“Reform UK are now the real opposition.”

Party chairman Zia Yusuf said: “History has been made today, as the centuries-long stranglehold on the centre-right of British politics by the Tories has finally been broken.

“Nigel Farage will be the next prime minister, and will return Britain to greatness.”

There were 131,680 Conservative members eligible to vote during the party’s leadership election to replace Rishi Sunak in the autumn.

The figure, revealed as Kemi Badenoch was announced as the new leader on November 2, was the lowest Tory level on record and a drop from the 2022 leadership contest when there were around 172,000 members.

Reform returned five MPs to the Commons at the general election in July, including Mr Farage in Clacton.

A Conservative Party spokesman said: “Reform has delivered a Labour Government that has cruelly cut winter fuel payments for 10 million pensioners, put the future of family farming and food security at risk, and launched a devastating raid on jobs which will leave working people paying the price.

“A vote for Reform this coming May is a vote for a Labour council – only the Conservatives can stop this.”

Unlike other political parties, Reform was set up as a limited company, and in September Mr Farage announced that he would change the ownership structure so that it would be owned by members.

“I no longer need to control this party,” he said at the time.

In a video posted on X, he said: “We will change the structure of the party from one limited by shares to a company limited by guarantee, and that means it’s the members of Reform that will own this party.”

There is no doubt Reform had a very good autumn. I think they capitalised off some of Labour’s early mistakes but also the fact the Conservative brand is still struggling. They’ve clearly got momentum

A research briefing published by the House of Commons Library in 2022 said comparing party membership numbers can be “difficult”, citing there not being a uniformly recognised definition of membership, or an established method to monitor it.

Luke Tryl, director of the More in Common think tank similarly told the PA news agency it is an “opaque” process.

“Parties are notoriously opaque about this sort of thing,” he said, also raising the idea that it is unknown whether the Conservatives have added any new members since their leadership election.

He later added: “It’s very opaque and murky as a metric anyway.”

With regard to Reform, Mr Tryl indicated that one of the challenges for the party will be whether membership converts to campaigners.

He told PA: “There is no doubt Reform had a very good autumn. I think they capitalised off some of Labour’s early mistakes but also the fact the Conservative brand is still struggling. They’ve clearly got momentum.”

Discussing Reform’s membership, he later said: “We know that lots of Reform’s most vocal supporters are very online.

“Do those people who are very online and joined up… do they also go out and pound the streets, deliver leaflets, canvass, that sort of thing?

“That remains an open question.”

A Labour Party spokesman said: “While the Tories and Reform pick fights with one another yet again, this Labour Government is getting on with delivering the change the British people voted for in July.”