But voters should take these claims with a pinch of salt as they head to ballot boxes on Thursday – because when you dig into the figures, they turn out to be pretty meaningless. Neither party is using data that can accurately make those comparisons.
A few weeks ago, the Conservatives claimed their councils save families around £100 a year more than those led by Labour and Liberal Democrats using data on the band D council tax charge for each council. But band D tax doesn’t bear much relation to how much tax households in a council area actually pay.
In each English council area, tax varies depending on the value of your home. Homes are valued on a national scale from band A (the cheapest) to band H (the most expensive). So band D is nominally the “middle” band, which is why it’s often used.
But it isn’t actually the average. Across England, two thirds of homes are in bands A to C – so a band D bill is actually higher than most households pay. Using band D rates can make tax in areas with a larger number of more expensive homes look lower than in areas with cheaper homes.
Look at Darlington and Southend-on-Sea. Darlington charges on average £4 less per residence than Southend – but its band D rate is £124 more.
That’s because Darlington has more homes below Band D than Southend. While both councils need to collect roughly the same amount of money per household, the band D rate is higher in Darlington because these households are essentially counterbalancing lower tax on cheaper homes to a greater extent than in Southend.
And because of the types of councils the two parties tend to control, this may artificially make tax in Conservative areas look lower than in Labour areas.
Labour’s comparison doesn’t fare much better. Last month, the party claimed that people living under its councils pay on average £351 less council tax than those in Conservative areas.
While Conservatives used band D rates, Labour used data on the average tax per household, which at least bears more resemblance to real life.
The problem is that, in some cases, it shows money being collected by Labour councils, when most of that tax level is actually set by Conservative councils.
This is because in England there are two types of local authority. “Billing authorities” collect council taxes, and “precepting authorities” instruct billing authorities to collect that tax on their behalf. Labour-controlled Burnley borough council, for example, collects council tax – most of which goes to Conservative-run Lancashire county council.
But in the data, these amounts aren’t split out. So in their calculations, Labour included the tax charged by 26 Labour district councils, even though most of this is actually set by Conservative county councils. The result? A large part of that “Labour” average is calculated using tax set by Conservative councils.
The bigger problem with all this is that the numbers wouldn’t tell us anything very significant even if the sums were done perfectly. A comparison painstakingly worked out — with data showing the average tax paid, per household, to each billing and each precepting authority — still wouldn’t give you especially useful information about how to vote if you wanted lower (or indeed higher) taxes.
That’s because there are many things that influence how much council tax you pay – the party in control isn’t the only (or arguably even the main) factor.
Areas with an older population may need to collect more tax – not because of the party in charge, but because of higher social care costs. The same’s true of areas with high social housing needs. Basic functions like collecting bins may cost different amounts in sprawling, sparsely populated rural communities versus smaller, dense urban ones. Areas with more businesses may be able to charge lower council tax because they collect more income from business rates. And so on.
Ideally, neither party would campaign on misleading claims like these. But realistically you’re likely to hear them more and more in the next few days.
Next time you do, it’s worth remembering just how meaningless they really are.
Abbas Panjwani is a factchecker at Full Fact