The UK goes to the polls tomorrow in the first major electoral test since Boris Johnson secured his 80-seat majority in the 2019 General Election.

Voting will take place in Scotland, Wales, and parts of England (including London) while voters in Northern Ireland are set to elect members of the Northern Ireland Assembly. In theory, local government elections should be concerned with the delivery of public services like bin collections – but, increasingly, they have come to be seen as an opportunity for the public to pass a verdict on the Government of the day.

The last six months have been tumultuous for Boris Johnson. Beginning with the Owen Paterson affair, where the Government was unable to whip its own MPs in favour of changing the rules on lobbying, and then the ongoing investigations into allegations that the PM and No10 staff broke lockdown rules. Many MPs have said they will decide whether to call for the PM to resign depending on tomorrow’s results and a disastrous start to the campaign, which included an MP having to resign after admitting to watching porn in the House of Commons chamber, makes this a moment of danger for Boris Johnson.

The outcome will also be a key test of whether Labour leader Sir Keir Starmer has been able to cement the Labour Party in the eyes of voters as a viable alternative. Commentators will be closely watching the former Labour-supporting areas in the North and Midlands that deserted the party under Jeremy Corbyn and reading the entrails for clues as to how Starmer will do in a General Election. Starmer’s team will be acutely aware that, at this stage in the electoral cycle and ahead of a tectonic change in politics, both Thatcher and Blair won big at the local elections and were miles ahead in the polls.

No pressure then.

Both parties, therefore, have embarked on the ritual dance of expectation management, designed to maximise or minimise impact depending on your point of view. Sources close to No10 say that the Tories are in danger of losing up to 800 seats in the knowledge that they can spin a more realistic loss of around 300 as a victory because it ‘exceeds’ expectations; a case of mid-term blues.

Similarly, Starmer’s team are playing down predictions that they might win a totemic victory in Tory held councils in places like Wandsworth, Westminster and Barnet, which are on a knife-edge, in the hope that they will do just that and can claim a national shift towards Labour.

The reality is neither party will do particularly badly, but neither will do particularly well either. For Johnson – the perennially lucky politician – the way that the elections have fallen means that those seats up for grabs in Labour-supporting places, like London, were already won in 2018. Labour is defending 43% of the 4,350 seats, a factor that will deny them the spectacle of councils changing hands and will reduce the threat to Boris Johnson’s leadership if MPs judge him to be an electoral asset.

That said, key battleground areas in places like Wolverhampton and Hartlepool where the Conservatives took constituency seats from Labour will be important in assessing the national mood. As will some of the Conservative versus Lib Dem contests, particularly in the Southwest where there is anger at the Government’s failure to deliver on promises to match European social funding following Brexit.

The other key geographical contest will be in Northern Ireland, where voters will also be electing members of the Northern Ireland Assembly. As my colleague, Austyn Close, pointed out in his recent podcast with senior NI political journalists, Northern Ireland is facing the prospect of Sinn Fein becoming, for the first time, the largest party at Stormont. The current poll average puts Sinn Féin support at 24%, against the Democratic Unionist Party’s 19%. A victory would allow Sinn Féin to nominate its deputy leader, Michelle O’Neill, as the new first minister. In practical terms not much would change as, under the power-sharing agreement, both parties must work together or not at all. However, in political terms, it represents a seismic shift and raises several questions about the future of the United Kingdom. The DUP leader, Geoffrey Donaldson, has already indicated that he will not participate in the Executive citing concerns about the NI protocol and fears about a referendum on Irish unification.

The key takeaway from the local elections, then, is not to look for dramatic tidal shifts but for evidence that shows whether the percentage share of the vote is holding for the Government or if Labour is benefiting from the cost-of-living crisis. The Conservatives took a 37% share of the vote in 2018 against Labour’s 36%. If the Tories manage to capture a percentage share that is in the low to mid-30s, that would suggest that neither party will be able to win outright in 2024.