Nigel Farage could topple Sir Keir Starmer, concerned Labour backbenchers have admitted.
The Reform UK leader commands a quarter of the public’s support, ahead of Labour on 24% and the Tories on 21%.
His party topped YouGov’s voter intention poll for the first time on Monday.
One Labour MP said: “I think it’s more about delivering economically and in public service improvements for left-behind towns. If people’s lives get better by the next General Election they will give us another term of office.”
They added: “People are impressed when you tell them on the doorstep about government deporting 16,500 illegal immigrants.”
Sir Keir’s popularity in the polls has tanked with his net favorability last month being -38%.
A Labour MP said: “I’m a little bit concerned. But it’s all the Nigel show at the moment and seven months into power, after all the big decisions, I’ll take where we are.
“If polls are still like this in four years I’ll be more worried.”
A senior politician in the party added that if Sir Keir can “grow the economy” Reform won’t be a threat.
Labour MPs have been scrambling to assess how their seat could be impacted by Reform’s rise after the bombshell poll was shared in Whatsapp groups.
Mr Farage said: “The consensus we’ve had for years doesn’t work.
“Ordinary folk get poorer, our borders are open, excess migration changes our communities.
“People want strong, patriotic leadership that actually cares about ordinary people.”
His party also recently topped a national opinion poll by Find Out Now, with 26%.
Reform UK is gearing up for the May 1 local and mayoral elections, which Mr Farage has said will be the party’s “first real test”.
The party has also been seeking to boost its coffers with donations, and Mr Farage met with Elon Musk amid rumours the Tesla boss was considering making a large donation.
But Mr Musk then said that the party needs a new leader and said Mr Farage “doesn’t have what it takes”.
But the Reform UK leader said they were now on good terms.
“He wanted me to go along a line that I didn’t want to go down. I don’t get bullied by anybody. I stand up for the principles that I believe in. Since then, we’ve had very cordial relations,” Mr Farage told the Today programme.