The electoral system forces the creation of unholy alliances within our two main parties
As we saw in the General Election (except in Scotland!) the chances for a third or fourth Party to break through in Westminster are negligible. UKIP and the Green Party gained 3.9m and 1.2m votes but only one of the 650 seats in Parliament each. It was ever thus. The LibDems took 25 years to build up sufficient local constituency strength to get 60 odd seats - then lost most of them in one go as their star fell from grace. First Past the Post favours the two main parties and only an earthquake can change that - as it did north of the border.
This is not a piece about electoral reform certain though I am that it is necessary. It is about the consequences of FPTP in respect of Parties' internal alliances. Harold Wilson called the Labour Party a "Broad church" - but the Conservatives have been no less broad over the years. Each of our two main parties is a coalition of people who believe different things. Sometimes VERY different things. But with one major, and a couple of minor exceptions these differences don't lead to splits. For (say) Dennis Skinner or (say) Peter Bone to stay in the Labour and Conservative parties respectively requires them reluctantly to accept a degree of conformity to party positions even though they don't endorse them.
The internal coalition in Labour or the Conservatives is arguably beneficial in respect of policy formation, but not always. Tony Blair created a unified Party in which, until the Iraq War, there was if not total agreement at least acceptance of policy. On the other hand the unfairly maligned Wilson/Callaghan Governments of the 1970s were close to succeeding in building a broad Social Democratic consensus both in the Party, and in the country. But that was stymied by the Labour Left both within the Government and outside. The winter of discontent of 1978/9 had fatal consequences for Labour and let Margaret Thatcher into Number 10. It also precipitated the Labour split and the formation of the SDP when Michael Foot became Labour leader. John Major fared better when faced with a similar challenge from the Tory Right in 1995 but was fatally wounded and lost office in the 1997 General Election.
Let's focus on what has been happening to our two major Parties for the last 50 years. They have (the SDP secession apart) held together - just. In the last Parliament only two Tory MPs jumped ship to UKIP. They were far from the only MPs sympathetic to the UKIP policy positions - but they no doubt judged that their chances of staying in Parliament were better as dissident Tories than as Kippers. They were right as it turned out - ask Mark Reckless ! In Labour no significant figure has left the Party at all – George Galloway excepted perhaps if you regards him as “significant”. The reason is the electoral system. If the number of MPs that a Party got was closer in percentage terms to its number of votes my guess is at least twenty or thirty Tory MPs would have joined Douglas Carswell in UKIP.
As far as the Left is concerned I have argued here that there are two distinct streams – one Socialist and the other Social Democratic. The candidacy of Jeremy Corbyn to be leader of the Party is revealing this starkly. In fact the broad church alliance is under threat for the first time since the early 1980s. There are even talks of a split, though I doubt this will happen. But if we had a more proportional voting system that split would be sure to happen on the Left as it would on the Right.
if the four political streams I identify in my article were to become distinct political Parties – i.e. if the current Party consensus in both Labour and the Conservatives broke down (this could only happen if we had electoral reform) the consequences would be interesting. There would almost certainly be a Left/Left or a Right/Right coalition – depending on the election outcome. The Left or the Right Coalition Government would be formed following policy negotiations – rather like those of 2010. That it was a formal alliance would be explicit – and maybe this would be better than the single Party broad church alliances that can be so fractious?