Calculation of how many seats Labour and the rest would have obtained under PR ignores the fact that the parties as we know them would not have existed under PR. Both Labour and the Conservatives would have long ago split and we would by now have four or five largish parties and a few fringe ones.
We have to accept that very few voters will get exactly what they want from any political party. It is more important to have a government whose policies can be supported, in general, by a majority of voters.
G F STEELE