Polling guru Sir John Curtice said the incoming results at the local elections so far indicate the “fracturing of British politics”.
He explained that Reform UK, which is expected to be the big winners of the contest, are “not quite at 30 per cent of the vote” and “none of the parties are very big” – marking a change from the two-party system that has dominated politics in England.
Labour has already suffered disastrous losses, with Nigel Farage claiming that the results so far show Reform is on course to win the next general election.
Early results saw Labour haemorrhage hundreds of councillors and lose control of eight local authorities across England, while Reform, the Greens and the Liberal Democrats all made gains.
The prime minister faces further heavy losses as vote counting continues throughout Friday in both English local elections and contests for the Scottish parliament and Welsh Senedd.
But Sir John told the BBC: “It may well be now that Labour lose rather less than the 1,500 seats that perhaps some people said was potentially the tipping point for attempts to unseat Keir Starmer.”
He said: “There is still a very long way to go and certainly what one has to say is this: the big picture is Reform are ahead.
“It’s clear that Reform are so far winning most votes in the elections that have been declared so far, in much the same way as they were in last year’s council elections.
“And they are basically being trailed by four parties that are all of them just a little bit below 20 per cent or so, somewhere between 15 and 20 per cent, but are actually at the moment quite difficult to disentangle.”
He continued: “But none of the parties are very big, let’s make that clear. Even Reform are probably not quite at 30 per cent of the vote, so the fracturing of British politics is underlined by these results and confirmed by them.”
He added that the Greens were struggling to convert votes into seats so far because they were getting “far too many creditable second and third places”.
Sir Keir has already faced speculation about his leadership, with The Times reporting overnight that energy secretary Ed Miliband had urged him to set out a timetable for his departure.
But deputy prime minister David Lammy urged his party not to play “pass the parcel” with the leadership in response to the election results.
Labour sources pointed to poor local election results under previous prime ministers, including Sir Tony Blair, who lost 1,100 councillors in 1999 but went on to win re-election in a landslide in 2001.
Meanwhile, Mr Farage hailed early results from Thursday’s local election as a sign his party was on course for victory at a general election that is still up to three years away.
A jubilant Mr Farage heralded a “historic change in British politics”, telling reporters “there is no more left-right” as his outfit was “scoring stunning percentages in traditional old Labour areas”.
The Reform leader compared the substantial gains to clearing Becher’s Brook, a famously difficult jump in the Grand National.
“If we cleared Becher’s Brook and landed well, we go on to win the Grand National.
“What is very clear to me is that our voters will stick with us now all the way through.”
With 38 of the 136 councils declaring their full results in the early hours of Friday, Reform’s gains exceeded 230 seats while Labour had lost more than 170.
Mr Farage’s party also took control of its first council of this set of contests, nabbing Newcastle-under-Lyme from the Conservatives.