Right, a new UK election means a new one of these.
To begin with, the electorate calculation, which was very quick as I could just paste in the fresh OSE spreadsheet over the old one. Not much change, as you'd expect given that only two years have passed - no change between the home nations, or within Scotland or Wales. The only changes happen in the West of England - Avon and Dorset lose a seat each, while Cornwall and Devon each gain one.
As in 2017, the only parties that crossed the 4% threshold were the Conservatives, Labour and the Liberal Democrats. The SNP came tantalisingly close, but at 3.9%, will have to make do with the fixed seats they are extremely likely to win in every Scottish constituency.
The first calculation on the nationwide level looks as follows:
Conservative 325
Labour 239
Liberal Democrats 86
Now, this is obviously not going to be what the result ends up looking like. For a start, we should deduct the 16 seats given to Northern Ireland here, none of which are likely to go to the big three nationwide parties. That gives us the following breakdown:
Conservative 317
Labour 233
Liberal Democrats 84
In Northern Ireland, meanwhile, both Alliance and SDLP broke 12%, enabling them to get fixed seats in the single NI constituency again (possibly for the first time ever in the Alliance's case). The seat breakdown there looks as follows:
DUP 6 (-3)
SF 4 (-3)
SDLP 3 (+3)
Alliance 3 (+3)