Thanks to the data compilation by Electoral Calculus, I was able to check how many seats the 2nd referendum parties had 50%+1 in vs the pro-brexit parties.
The hypothetical question this is supposed to answer is, if Labour, Lib Dems, Green etc. all pooled their votes where it mattered, AND the Tories, Brexit Party etc. all pooled their votes, how would the election have gone.
It isn't really of any real significance, but hey I was curious and I had the data.
First count:
Pro 2nd referendum parties included: Labour, Liberal Democrats, Greens, SNP, Plaid Cymru, SDLP, Alliance, Sinn Fein (also includes the speaker)
- >50% in 302 seats (incl 42 Tory seats, and the 7 Sinn Fein non-sitting MPs)
- below 50% but ahead of the pro-brexit parties in another 13 seats (incl 10 more Tory seats)
Pro brexit parties included: Conservatives, Brexit Party, UUP, DUP
- >50% in 322 seats (incl 1 Scottish Tory seat, 11 Labour seats, and the Alliance seat)
- below 50% but ahead of the pro-2nd referendum parties in another 13 seats (incl 2 more Labour seats)
That result isn't enough to answer the question though, because neither group has a majority, and some of those 26 seats where both groups are below 50% have other candidates from e.g. Independent Group for Change or UKIP which aren't exactly neutral on brexit.
The thing that resolves it is including
the Yorkshire Party in the pro-brexit group, even though they only got ~1000 votes in each seat, that's enough to brings the group to >50% in an additional 4 seats, bringing the total to 326, which is a majority.
So even though the pro 2nd referendum parties have >50% of the votes overall, they aren't in the right places for a FPTP election.
(Though if the pro brexit parties *didn't* also co-operate, the pro 2nd referendum group did have enough votes to win in 345 seats. LAB 246, SNP 53, LIB 28, SF 8, PC 4, SDLP 3, Alliance 2, Green 1)
In case anyone wants to figure out the last 22 seats, in 20 of them including one other candidate would bring one group or the other to 50%: Independent Group for Change, David Gauke, the Liberal Party, Aontu, North East Party, UKIP (x2), Libertarian, Animal Welfare Party, Monster Raving Loony Party, Gwlad Gwlad, Ashfield Independents, Heavy Woollen District Independents, Burnley & Padiham Independent Party, Edmund Fordham, Chris Williamson, Watts Stelling, Anne Milton, Paul Crosland, Scott Marmion. Then Bury South and Esher and Walton depend on multiple other candidates.
