He told Sky News there was probably “a lot of surprises” still to come for Labour, after the Conservative Jill Mortimer won the Hartlepool by-election with nearly double the Labour vote and a swing of almost 16 per cent.
Professor Travers, a local government expert and director of LSE London, said if the pattern is repeated elsewhere: “These results could be substantially worse for Labour I think than even they were expecting 24-hours ago.”
Asked how unusual it was for a governing party to win a by-election, Professor Travers replied: “It’s very very unusual. It’s happened perhaps twice since the 1980s.”
He added: “For a party of opposition to be losing seats to the Government party in local elections is also unprecedented.”
Prof Travers said: “It looks as if, certainly in the less urban parts in the Midlands and the North, that the votes that used to be Labour votes have gone to UKIP because of Brexit and then on to the Conservative Party.
“It just suggests that the Labour Party has got an even larger, an even higher amount of decline than even they thought they had.”
Asked to explain the success of the Tories, he replied: “I think there is still the shadow of Brexit here. People who went from Labour to UKIP now appear to be comfortable going from UKIP to the Conservatives.
“It’s impossible to deny that Boris Johnson as the Conservative leader is a remarkable election winner. He won two elections as Mayor of London, one national General Election.
“It looks as if his image, his way of doing things appeals to voters who at one point voted Labour.
“I think the other factor is the Labour Party, after a very bad election in 2019 under the leadership of Jeremy Corbyn, is still on the way down.
“So if you add all these things together, Labour is going to have to admit this will have been a bad set of results and concede that they haven’t stopped going down.
“Whereas the Conservatives are in a remarkably strong position for a party in Government at this stage of a Parliament and having been in power for so long.”
Another election expert Lord Hayward described the Hartlepool results as “staggering” and said he never expected such a large margin.
The Tory peer said: “I think it tells us along with a number of the other results in Harlow, Redditch and Nuneaton, that what we would regard as blue collar England is moving significantly towards the Conservatives.
“It’s not just a Hartlepool result, it’s a result from other parts of the country as well.
“I think there are some signs in places like Essex and more traditional rural parts of Northumberland and the like that actually the more traditional Tory areas are not swinging as heavily as the blue collar areas such as Hartlepool and Sunderland and the like.”
Asked to define a typical Conservative voter now, he replied: “The demographics of England’s voting habit have changed. Education and wealth is no longer as clear a decider as it used to be – effectively class in one form or another.
“You can draw up a typical Conservative in the south of England but they hold that support less strongly than many of those people in the Midlands and the North.”
Asked if we were moving away from a class-based society, he replied: “Yes I think we are. There’s no question.
“When I first joined the Tory party and I joined it in Maidenhead and everybody would say that’s an archetypal Tory area.
“Now we’re in the position whereby traditional Labour areas which when I was a Member of Parliament returned Labour MPs with huge majorities are now voting Conservatives.
“And the traditional Conservative areas in many cases are still voting for the Conservative Party but not as strongly. They haven’t moved as much towards the Conservative Party as the other traditional Labour areas have.”
Steve Reed, shadow secretary for communities and local government, described Labour’s defeat at the Hartlepool by-election to Conservative candidate Jill Mortimer as “absolutely shattering”.
Labour’s defeated Hartlepool candidate Dr Paul Williams tweeted: “A massive thank you to everyone in Hartlepool who voted for me, and to the incredible Labour volunteers who worked so hard. “Congrats to Jill Mortimer. I’m off to do the important job now of taking the kids to school.”
Results of the elections- which also include the Welsh Parliament, police and crime commissioners and English local authorities and mayors - are expected to continue filtering through until Monday.