General election 2017: What will we learn from the local election results?
Results from this Thursday's ballot might give a strong indication of how 8 June will go
Local elections take place across the UK this Thursday 4 May – a month before the snap general election called for 8 June by Theresa May.
There are 4,851 council seats being contested in England, Scotland and Wales.
So will we learn from the local results about how the general election will go?
How will the results be analysed?
The results of the local elections will be used to calculate each party's "projected national vote share", working out how many people would have voted for each party if every voter in the UK had turned out for the local ballots. In 2013's local elections, for instance, Labour got 29 per cent, the Tories 25 per cent, Ukip 23 per cent and the Lib Dems 14 per cent.
However, projected national vote share should not be taken as representative of how people will actually vote in a general election, when they often have different priorities. Added to that, the UK's first-past-the-post system means vote share does not translate neatly into seats in the Commons.
What is the usual pattern?
According to Stephen Bush of the New Statesman, "a good rule of thumb for predicting general elections is to look at local election results, and assume that the government will do a bit better and the opposition parties will do significantly worse".
Local results are a "much better guide to the next general election than anything the polls might do".
Usually, adds Bush, if local elections take place in a year when there is no general election, voters use them as a chance to kick back against whoever is in power. In years when both take place, they are more restrained – and the ruling party does better.
Will that hold true this year?
Generally, local and general elections in the same year are held on the same day. As that's not the case in 2017, the usual pattern might not hold true and the Conservatives might do even better than a ruling party would expect. There is no way to be sure.
What do Labour expect at the local elections?
According to the Daily Telegraph, polling suggests Labour could lose as many as 125 council seats on 4 May, "which would be devastating for the opposition party".
What about the turnout?
You might expect that voters might give the council elections a miss if they know they will have to turn out to the polling stations a few weeks later for a more important ballot. But the numbers actually show they tend to be "higher turnout affairs", says Bush.