On 4 May seven in ten voters in England will choose more than 8,000 councillors on 230 councils. With 152 of those local authorities selecting every seat, expect some dramatic results and considerable change.

The Conservatives could lose one third of their seats and control of half their councils. Labour could, and arguably should, finally become the largest party of local government, a position it hasn't held for more than 20 years.

Both parties could take a hit from the Liberal Democrats and Greens but pay attention too to the number of Independent councillors re-elected. That could tell us much about people's enthusiasm for the two most likely contenders for power.

In fact, these seats were last contested seven months ahead of the 2019 general election and the story then was one of voter dissatisfaction with the Conservatives and Labour.

Theresa May's Tories made a net loss of 1,400 seats and lost majority control of 47 councils. Jeremy Corbyn's Labour also made a net loss - of 86 seats - a rare feat for a main opposition party. All others made net gains.

Can Labour become the largest party in local government?

The lack of Labour progress in recent local elections means the Conservatives still have more councillors and control more councils than any other party. But that might be about to change.

Defending more than 3,000 seats (over half their total in England) when the national party is so unpopular means the possibilities for disaster are real.

Labour benefits from the geography of this election round.

Instead of defending its heartlands, it has two goals: recover territory lost in 2019, and more ambitiously, recreate the conditions of the mid 1990s that helped Tony Blair's New Labour to success in Tory territories.

The Conservative/Labour battleground

The Tees Valley provides the best example for a Labour recovery in the so-called 'red wall'. In 2019 the party lost four of the five councils here, including Middlesbrough which it had controlled for the previous 46 years.

Here and elsewhere, it was competition from Independents and small community-based groups that proved Labour's undoing.

Now the party needs only a couple of gains to resume normal service, but replacing embedded Independent councillors is rarely easy.

Read more: All you need to know about the May vote

The Conservatives continue to battle strongly in Hartlepool, where just two years ago Labour was embarrassed by the highly unusual loss of a parliamentary by-election to the governing party.

Darlington had the pleasure of a visit from Prime Minister Rishi Sunak during the campaign. It's next to his North Yorkshire constituency and the one Tees council the Conservatives run, albeit as a minority administration.

Further south in Stoke on Trent, Labour's collapse began in the early noughties. Where once Labour council benches were full to overflowing, any promise of recovery was scuppered by Independents and Conservatives producing a hung council.

Dudley and Walsall provide two further examples where Labour has taken a step backwards. Losses to UKIP initially then turned into Conservatives drawing level and advancing to majority control in 2021.

Though Labour managed to win Walsall in 1995 under Blair, its vote there is now so poorly distributed that equal shares in 2022 saw the Conservatives winning 13 seats to Labour's 7.

Labour must gain seats this year but seizing council control is probably beyond it.

There is no faulting its ambition though, party leader Sir Keir Starmer kicking off the campaign in Swindon before heading to Medway. It's been 23 years since Labour lost its majority in the former, while Labour have never controlled the latter.

A third of Swindon's seats are up, and the party will be looking to win more than the 12 they did in 2022. In 1997, Labour secured two parliamentary seats there and a repeat is required for a majority at the next general election.

Medway is a more ambitious target but a whole council election on new ward boundaries provides potential. Boundary changes help Labour's cause marginally and the party has attracted more support in recent elections.

In 1997, Labour came within two seats of winning. Should it succeed this time then Starmer would rightfully claim this as an important victory.

The Liberal Democrat challenge in southern England

While Labour is the chief challenger to the Conservatives, the Liberal Democrats - former coalition partners lest we forget - are also likely to inflict damage on the governing party.

The party are desperate to show they are a substantive threat to the Tories across southern England. They need a minimum of 50 net gains to do so but would be happier with 150 or more.

One target area is Surrey where they already hold some councils and aim to capitalise on a slump in Conservative support. So, keep an eye on Guildford, Surrey Heath (Michael Gove's backyard) and Waverley (Chancellor Jeremy Hunt's area).

If the Lib Dems make the necessary gains, they may build on their spectacular 2018 takeover of South Cambridgeshire by also taking East Cambridgeshire for the first time in 20 years.

How to read the results

The challenge for all parties is to defend or advance on their 2019 position - and that was a mixed bag.

The Conservatives did poorly so have less far to fall but keen observers will be watching how Independents and smaller parties fare.

If the seats won in 2019 are retained, then that will suggest Labour is struggling to convince voters. And that matters for a general election.

For the Conservatives losing fewer than 500 seats (net) might leave them feeling relatively unscathed. At 750 net losses, they could say Labour isn't performing as well at the ballot box as they are in the polls.

However, making more than a 1,000 net seat losses and very likely losing majority control in over half the 82 councils they are defending will be difficult to spin.

To win an overall majority in Parliament, Labour needs a swing larger than that achieved by Tony Blair in 1997 - which remains the post-war record. It'll want net gains in the mid to high hundreds, and to win back key councils, in order to say it's on track for that.

With 62 councils counting overnight the direction of travel should be known by breakfast. Friday counts from noon onwards will supply the fine detail.

Dr Hannah Bunting is a lecturer in Quantitative British Politics at the University of Exeter.
Professor Michael Thrasher is an Associate member at Nuffield College, University of Oxford.