What if…

I’d been wondering about this. What if the LDs found they just couldn’t get PR, gave up the whole third-party thing as a bad job, and merged with the Labour party? Well, on this election’s numbers:

                                   Party     Votes  Seats
=========================================================
                                  Labour: 15389322    433
                            Conservative: 10658048    189
               Democratic Unionist Party:   168216      8
                 Scottish National Party:   491386      5
                               Sinn Fein:   171942      5
        Social Democratic & Labour Party:   110970      3
                             Plaid Cymru:   163196      1
                             Independent:   140537      1
                          Alliance Party:    42762      1
                                 Speaker:    22860      1

The outcome is even more extreme if they merged with the Conservatives instead:

                                   Party     Votes  Seats
=========================================================
                            Conservative: 17464146    483
                                  Labour:  8583224    140
               Democratic Unionist Party:   168216      8
                               Sinn Fein:   171942      5
                             Plaid Cymru:   163196      3
        Social Democratic & Labour Party:   110970      3
                 Scottish National Party:   491386      2
                             Independent:   140537      1
                          Alliance Party:    42762      1
                                 Speaker:    22860      1

The actual outcome in the same format, just for completeness:

                                   Party     Votes  Seats
=========================================================
                            Conservative: 10658048    305
                                  Labour:  8583224    257
                        Liberal Democrat:  6806098     56
               Democratic Unionist Party:   168216      8
                 Scottish National Party:   491386      6
                               Sinn Fein:   171942      5
                             Plaid Cymru:   163196      3
        Social Democratic & Labour Party:   110970      3
                             Independent:   140537      1
                          Alliance Party:    42762      1
                                   Green:   285616      1
                                 Speaker:    22860      1

(In each case only parties winning at least one seat are shown. Errors and omissions (such as Thirsk & Malton) excepted.)