They might be local elections, but the results of thousands of votes being held on Thursday around Britain are likely to have major ramifications for the national government.

If results go as expected, many analysts are predicting it could be terminal for the leadership of embattled Prime Minister Sir Keir Starmer.

Less than two years after steering the Labour Party to a landslide general election victory, Sir Keir’s popularity has plummeted in many parts of the United Kingdom.

Labour is expected to be swept out of power in the Welsh parliament as well as dozens of councils across England. Long-held hopes of regaining power in the Scottish Parliament look set to be dashed, too, in a major disappointment for the party’s activists north of the border.

The make-up of Sir Keir’s government is not at risk, because another general election is not due to be held until 2029. But national parties dominate local politics in the UK, and Thursday’s votes are being couched as a referendum on the PM’s agenda.

If opinion polls are correct, Labour’s defeats are predicted to be catastrophic, although the picture for other major parties is not much better.

They show smaller, in some cases more radical, options on the ballot enjoying a surge in support.

In England, for example, the right-wing Reform UK and left-wing Green Party are both likely to take control of multiple councils, when about 5,000 seats across 136 municipalities go up for grabs on Thursday.

Hackney, in east London, has been run by Labour since the 1970s. The party currently holds 50 of the possible 57 seats (British councils are a lot larger than Australians might be used to). Some opinion polls are showing they could be reduced to around 15.

“There are some really good local councillors, but I want a message to go to Keir Starmer to say I’m really not happy with what he’s been doing,” one woman in the area told the ABC ahead of the vote.

If the predictions are correct, Hackney is about to turn Green.

Zoë Garbett is the party’s candidate for mayor, and said while she had been door knocking during the campaign, people have told her they “feel let down by Labour”.

“It really does feel like people are [going to be] voting out of those frustrations, but they can also see what we’re offering as the Green Party,” Ms Garbett said.

For Sir Keir, ‘it’s a matter of when, not if’

In July 2024, Sir Keir, a former chief crown prosecutor, stormed to power in the UK, ending the centre-right Conservative Party’s 14-year reign.

Despite the magnitude of Labour’s victory (they won more than 400 seats out of 650), data from multiple samples showed Sir Keir was not personally popular. Some analysts have pointed out he benefited because many voters were desperate to ditch the Conservative Party from government.

A cost-of-living crisis, key policy backflips, questions over expenses and high-profile resignations have since plagued his leadership.

The government has continually claimed that its policies are designed to promote long-term economic stability in Britain, and that net migration to the country has dropped significantly since it took power — something considered a key election issue for many voters.

However, it was the appointment of Labour stalwart and former business secretary Lord Peter Mandelson as ambassador to the US, knowing he had links to the late sex offender Jeffrey Epstein, that has caused the most controversy.

Lord Mandelson was sacked last year, but the scandal has continued to reverberate through the government.

Many experts now believe Sir Keir will not last as prime minister. Although, right now, no Labour colleagues have publicly launched a challenge.

“I think if you talk to a lot of MPs they will still say it’s a matter of when, not if, but they have absolutely no idea when the when is,” UK political editor at Politico, Dan Bloom, said.

Sir Keir’s most senior colleagues are still supporting him, and there are plenty of Labour people who want him to defy his critics and fight the next general election, expected to be held in around three years.

“If we ignore the social media trolls and bots and ignore the self-interest of billionaire-owned right-wing press, the quiet, reasonable majority of people do not want a change of prime minister,” Labour MP Dr Allison Gardner told the House of Commons last month.

Question marks surround the timing of a potential leadership change. No Labour MPs have publicly expressed an intention to run against the PM, although that does not mean that political rivals, like Manchester Mayor Andy Burnham, are not circling.

The war in the Middle East is also creating geopolitical uncertainty that could delay any would-be challenger.

Nevertheless, these local elections are being watched closely by many in the UK parliament.

Labour is not the only major party struggling. The Conservatives are also under threat.

“There is a really interesting thing happening here where this is not just about Keir Starmer or the Labour party, this is about a kind of move away from establishment parties in the UK,” Mr Bloom said.

In London, the Green Party is expected to scoop up many of Labour’s inner-city seats. Elsewhere, Reform UK, led by anti-immigration campaigner Nigel Farage, is polling strongly.

He told a rally in March: “The voters in these areas can deliver a decisive blow and a blow that would mean Starmer would be out of office by the end of May, isn’t that worth fighting for?”

Many polls are predicting Reform UK will be the big winner on Thursday. The party could pick up well over 1,000 local council seats. The Greens are expected to win around 500.

“You’re essentially getting this chipping away at Labour’s vote from right and left,” Mr Bloom said.

The increased popularity has not been all smooth sailing for the minor parties, however. Despite Mr Farage saying Reform had improved its vetting process, several candidates have been accused of making racist social media posts ahead of the local elections.

Meanwhile, last week, two Green Party candidates in London were arrested over making allegedly antisemitic social media posts.

Indeed, the treatment of British Jews has been a talking point, particularly in the final fortnight of campaigning, amid a spate of attacks on the community.

Earlier this week, Sir Keir convened a Tackling Antisemitism Forum at 10 Downing Street, while Conservatives leader Kemi Badenoch went viral online after clashing with a protester at an event over the issue.

Overall, however, the soaring cost of living has been consistently ranked as the biggest concern among Brits.

Voting in the UK, including at local elections, is not compulsory. Polls open at 8am local time (5pm AEST) and results are expected to be known in the coming days.