Sir Keir Starmer has said “fantastic” council results show Labour is on course to win the next general election, as Rishi Sunak remained defiant despite heavy losses.

The Labour leader told jubilant supporters they are progressing towards a majority in Westminster, as local election results on Friday saw his party seize multiple battlegrounds from the Tories.

The Liberal Democrats also made gains as the Tories lost control of 16 councils and had more than 220 councillors ousted across England, with more than a third of authorities declared.

Mr Sunak conceded the results were “disappointing” but said he was “not detecting any massive groundswell of movement towards the Labour Party or excitement for its agenda”.

But the Tories will be concerned by losses in the North, South and Midlands as the prospect of a general election in 2024 looms.

Labour seized control of Swindon council, which contains two Westminster battlegrounds and had been held by the Tories for 20 years, on top of the capture of East Staffordshire and Medway.

Sir Keir’s party will run the Kent authority for the first time since 1998, with the outgoing Conservative council leader telling No 10 to “get their act together” on several fronts.

The opposition was also boosted by gaining Stoke-on-Trent and Plymouth, as the Lib Dems won Windsor & Maidenhead from the Conservatives.

A day of celebration for Sir Keir started with a visit to Medway, where he welcomed “fantastic results across the country” in “places we need to win”, citing victories in Plymouth, Stoke and Middlesbrough, where his party won the mayoralty.

“Make no mistake, we are on course for a Labour majority at the next general election,” Sir Keir said.

“We’ve changed our party. We’ve won the trust, the confidence of voters, and now we can go on to change our country. Change is possible. A better Britain is possible.”

In central London, Mr Sunak was understood to have thanked staff for their efforts, and said the results were always going to be tough but that the state of play has improved since he took over six months ago after the leaderships of Boris Johnson and Liz Truss.

He went on to tell broadcasters it was “hard to draw firm conclusions” from the initial results, with a more than a quarter of councils having declared.

The Prime Minister said: “It’s always disappointing to lose hardworking Conservative councillors, they’re friends, they’re colleagues and I’m so grateful to them for everything they’ve done.

“But in terms of the results, it’s still early. We’ve just had a quarter of the results in, but what I am going to carry on doing is delivering on the people’s priorities.”

Mr Sunak cited his priorities as halving inflation, growing the economy, reducing debt, cutting NHS waiting lists and “stopping the boats”, adding: “That’s what people want us to do. That’s what I’m going to keep hard at doing.”

The Prime Minister said the Tories are “making progress in key electoral battlegrounds like Peterborough, Bassetlaw, Sandwell”.

The inroads for the Tories are debatable. In Sandwell, they have gained two of 24 seats, while Labour has gained four and held 18 more.

In Hertsmere, where Deputy Prime Minister Oliver Dowden is MP, the Tories have lost control of the council, with 13 councillors voted out, while Labour has gained seven and the Lib Dems six.

The Conservatives lost control of Welwyn Hatfield – represented in Parliament by Energy Secretary Grant Shapps – where both the Lib Dems and Labour made gains.

The Tories also lost overall control in North West Leicestershire, Brentwood, East Lindsey and Hertsmere, as Labour won Blackpool.

Polling expert Professor Sir John Curtice told the PA news agency the “jury is still out” on whether Labour has made progress as a party and said it is not experiencing the level of success seen ahead of Sir Tony Blair’s 1997 landslide.

“Labour are going to have their biggest lead over the Conservatives in terms of votes than at any point since 2010, but it’s going to be as much to do with the Conservatives being down as much as it is Labour being up,” he said.

Government minister and local MP Johnny Mercer said Labour gaining control of Plymouth, where the Tories had run a minority administration, was “terrible”.

The veterans minister blamed the loss on local factors including the council’s decision to fell dozens of trees in the city centre, as he defended Mr Sunak as the “strong leader this country needs”.

Stoke-on-Trent North Tory MP Jonathan Gullis told Sky News councillors have “suffered because, at the end of 2022, the Conservative Party as a brand was certainly damaged”.

In Tamworth, the seat of scandal-hit former Tory whip Chris Pincher, Labour has made seven gains, pushing it from Conservative into no overall control.

But Labour’s attempts to regain Hull from the Lib Dems failed, with Sir Ed Davey’s party tightening its grip on the authority.

With full results from 87 of the 230 councils where elections were held:

– The Tories have lost 16 councils and suffered a net loss of 228 councillors.

– Labour has gained control of five councils and added 180 councillors.

– The Liberal Democrats have gained one council and 77 councillors.

– The Green Party has gained 26 councillors.

Labour expects to have its best local election results since 1997, with an equivalent vote share lead of at least 8% over the Tories, which could result in a majority Labour government if repeated in a Westminster contest.

Liberal Democrat leader Sir Ed said it has been a “groundbreaking night” for his party.

“We are exceeding all expectations. We have delivered a hammer blow to the Conservative Party in the blue wall ahead of next year’s general election,” he said.

But the elections were described as a “dark day for British democracy” by campaigners opposed to the introduction of photo ID, who claimed thousands of people were denied their right to vote.

The contests were the first to be held under new rules requiring voters to carry photographic ID and the elections watchdog said some people were turned away from polling stations.

An Electoral Commission spokesman said: “We already know from our research that the ID requirement posed a greater challenge for some groups in society and that some people were regrettably unable to vote as a result.

“It will be essential to understand the extent of this impact, and the reasons behind it, before a final view can be taken on how the policy has worked in practice and what can be learned for future elections.”