Voters have been warned that a cross for Reform UK on the ballot paper is a vote for Sir Keir Starmer, as the party claimed third place in both of last night’s by-elections.

Prime Minister Rishi Sunak said the “actual choice” at the general election is “between me and him”, referring to the Labour leader.

Meanwhile, the Conservative Party chairman Richard Holden said Reform UK “want to see Sir Keir Starmer in Downing Street”.

Reform gained 13% of the vote in Wellingborough and 10% in Kingswood, with the party leader Richard Tice stating it is “solidifying” itself as the third-largest political party in the UK.

Speaking to reporters, Mr Tice said: “We’re essentially now solidifying ourselves as the third largest political party, way ahead of the Lib Dems, who seem to be disappearing away.

“It’s quite clear that the voters have rejected the incumbent Conservative Party because frankly they’ve broken Britain.”

Mr Tice said the Conservatives should step aside and let him take on Sir Keir as he “would beat him hands down”.

He told GB News: “People are realising that they’re tired, they’re old, they’re toxic. They’ve had their chance, they’ve blown it.

“Frankly, they should stand aside now, having messed up, let me take on Keir Starmer head-to-head, I’d beat him hands down.”

In the heavily pro-Leave constituency of Wellingborough, Reform finished third with 13% of the vote, its best performance at a by-election, which candidate Ben Habib hailed as “remarkable”.

Asked why people voted for him, he said: “People are absolutely fed up with the manner in which this country is being governed.”

On whether Reform is letting Labour leader Sir Keir Starmer into Number 10, he said: “The only reason Labour win, if Labour win, is because the Tory party is utterly useless.

“The Conservative Party is the problem and they need to go.”

Meanwhile in Kingston, Rupert Lowe won 10% of the vote.

Following the double by-election defeat, when Mr Sunak was asked whether he was more concerned about Reform UK or Labour during a visit to Harlow, Essex, he said: “A vote for anyone who isn’t the Conservative candidate, whether that’s Reform or anyone else, is just a vote to put Keir Starmer in power.

“That’s the actual choice at the general election, between me and him, between the Conservatives and Labour.

“Now I believe our plan is working. At the start of this year we’re heading in the right direction, taxes are coming down, inflation is falling, and if we stick with that plan we can deliver everyone a brighter future.”

Conservative Party chairman Mr Holden said Reform “aren’t challenging realistically for seats” and that the general election would be between Labour and his party.

Speaking to BBC Breakfast, he said: “Their ambition is to block Conservatives winning seats and therefore put Keir Starmer into Downing Street.

“They’ve made it very clear … that’s what Reform UK want to do, they want to see Keir Starmer in Downing Street and not have a Conservative government.”

He added: “Reform aren’t challenging realistically for seats. This general elections is going to be a battle between the Conservatives and the Labour Party.

“All Reform are going to do, as they’ve said themselves, is help put Keir Starmer and Labour into Downing Street.”

Asked if Prime Minister Rishi Sunak needs to appease the right of the Conservative Party, Mr Holden said: “If the right of the British politics and the centre and centre-right – that broad church which is the Conservative Party – doesn’t unite, then we will see a Labour victory.”

He added: “I believe we have every opportunity to win the next general election, I think we definitely can do it, but that means we have got to come together as a party, unite in the best interests of the country, deliver those things that we’ve promised, work together as a party to do that.”