Reform UK has secured victory by six votes over Labour in the first by-election test for Keir Starmer as Prime Minister, with party leader Nigel Farage claiming the government's failure to clamp down on migrants lay behind the result.
The narrow victory for new MP Sarah Pochin in Runcorn and Helsby, in north-west England, saw Reform taking a constituency which Labour won with a majority of almost 14,700 less than 12 months ago.
The result came as Reform made gains against both Labour and the Conservatives across England in local contests, with Mr Farage claiming a “big moment” was taking place in politics.
Andrea Jenkyns was elected for Reform UK as the first Greater Lincolnshire mayor with a majority of almost 40,000 over the Conservatives.
“We are now the opposition,” said Mr Farage. “We are not a protest party, even though there is much to protest about.”
Mr Starmer noted the frustration driving the vote and said he "got it" that voters wanted more from the government he has headed since last July. : “I am determined that we will go further and faster on the change that people want to see,” he said.
Ms Pochin becomes the party's fifth MP. Although the party won five seats in last year's general election, Rupert Lowe was suspended after criticising Mr Farage's leadership.
Speaking on Friday morning after the Runcorn result was declared after a recount, Mr Farage said Labour's support had collapsed in its heartlands.
He put the victory down to a “loss of confidence” in Labour, and a sense that the Conservatives don't stand for “patriotic” values. His party has campaigned on an anti-migrant platform.
He said there were 750 young men who had crossed the English Channel living in the constituency and “causing great alarm in many streets”, a feeling “bordering on resentment”.
He added: “Dover may be a long way away. It’s influence on this election was enormous.”
The number of migrants crossing the English Channel so far this year has reached 11,000 − just days after arrivals passed 10,000 in record time.
A total of 294 people made the journey in five boats on Wednesday, bringing the provisional total for the year to date to 11,074, according to the latest Home Office data.
Asked if he was scapegoating migrants for problems, Mr Farage said: “Why should I pay my taxes for people who illegally come into Britain, get free health care, immediate GP appointments, free dental appointments, spending money and full bed and breakfast paid for?
“There’s a sense here that something wrong and unfair is going on. The divisions are being created by weak British governments allowing people … from all over the world, undocumented young males of fighting age to come in to Britain in unprecedented numbers.”
Ms Jenkyns, a former Tory minister, gave a similar message, saying Reform would "reset Britain to its glorious past".
“We will tackle illegal migration. We’ve been working on policies," she said. “I say no to putting people in hotels. Tents are good enough for France, they should be good enough for here in Britain.”

The by-election was triggered when former Labour MP Mike Amesbury quit after admitting punching a constituent.
Amesbury won 53 per cent of the vote at the general election – and the defeat, along with Reform gains in other Labour heartlands, will cause unease in Downing Street.
The result was declared after a full recount took place, with just four votes separating Reform and Labour after the first count.
A Conservative representative said: “This result is a damning verdict on Keir Starmer’s leadership which has led to Labour losing a safe seat.”
Polling expert Sir John Curtice said Reform UK “are in business” following their victory. “They are a major challenge,” he said.

Local vote
More than 1,600 council seats were up for grabs across 23 local authorities while four regional mayors and two local mayors were being elected.
Reform swept to victory across more than half a dozen English councils, with counting continuing into Friday evening.
After final results were in from 16 of the 23 English councils holding elections, Reform had almost 500 councillors, after gaining 476 seats, with the Liberal Democrats in second place with 237, up 86.
The Conservatives had 199 seats, down 411, and Labour 56, after losing 137 seats, leaving Sir Keir Starmer’s party one behind the Greens, who were up 29, while independents had 55 councillors, down 61.
Labour Party chairwoman Ellie Reeves said the elections “were always going to be a challenge” for her party, because they were largely in areas “dominated by the Conservatives, often for decades”.
She said voters “aren’t yet fully feeling the benefit” of changes brought in since Mr Starmer took office.
Kemi Badenoch, the Conservative leader, said she needed time on to win back voters trust. “These were always going to be a very difficult set of elections coming off the high of 2021, and our historic defeat last year – and so it’s proving," she said.
Rejecting both parties assertions, Mr Farage said he wanted to “smash the two-party system”.