It’s political suicide for Labour to ditch first past the post

Proportional representation would fracture the party and cut if off from its history.

If the Labour Party can be described as a family, it’s not necessarily a close-knit and happy one. Its gatherings resemble something more like a meeting of extended families, with various second-cousins, great-aunts and the like nursing old grudges and resentments.

This is the party’s weakness, but also its strength: the Labour Party is a product not just of its history, but also of the UK’s first past the post electoral system, which requires a coalition of interests to combine into a broad party, one that in recent years managed to accommodate Jeremy Corbyn, Frank Field and Jess Phillips alike.

Advocates of proportional representation – a catch-all for a range of electoral systems that to differing degrees break the constituency link to make a party’s overall seats in parliament more accurately reflect its share of the vote – want Labour to change this. The movement won a symbolic victory at this year’s party conference, passing a motion to support PR.

This doesn’t mean Labour is committed to supporting the policy in practice, let alone to putting it in its manifesto. Supporters of PR, however, often seem baffled that anyone in Labour might oppose it. This should not be so confusing.

To be a Labour member is, ostensibly, to be committed to a Labour government for the UK – not a coalition government or some other sort, as PR would make more likely. In theory the two goals – proportional representation and Labour in power – are incompatible. This is countered with the idea that the UK has a “progressive majority” that could keep the Conservatives out of power for ever, if only the electoral system was changed. This shows how short memories are: proportional elections to the European Parliament often favoured the Conservatives and Ukip, while there is no shortage of European countries with proportional systems and hard-right governments.

[See also: Kwasi Kwarteng makes a cautious retreat]

The subtext of many people’s calls for Labour to support PR is “…so I can vote for someone other than you”. Some even say it out loud, so it’s not surprising that people working for the party have reason to pause. A political party is unlikely to be enthusiastic about voting against its own interests.

Parties are more than just vehicles for votes. The Labour Party is the product of a political movement and comes with a historical connection to the trade union movement, which would surely fragment if PR were introduced and different factions of the party separated. Something called “Labour” might survive, but it would be a much narrower party, its future reliant on coalitions – perhaps with parties to its left but perhaps, like the Liberal Democrats, with parties to its right. People may point to the survival of Labour in Wales and Scotland under PR, but these devolved systems owe much of their structure to the UK-wide parties, which still provide the glue to hold the coalitions together, at least in the former.

The politics of coalition are unpredictable: the government is decided more by the parliamentary maths than by the voters. When the result of an election is close, this can give extreme parties or positions a lot of power; even a single-issue party may get the chance to have their fringe view enacted to make up the numbers. In a first past the post system, this coalition-building happens before the election – in negotiations on a party’s policy platform and manifesto. It is not perfect, but it is perhaps more predictable to the voter.

Another leader, like Liz Truss after Boris Johnson, might come along and try to run a totally different agenda with the same party, but British parliamentary maths makes that harder than it looks. PR advocates say one system is automatically better. The reality is every system has its upsides and downsides. It is provably mathematically impossible to design a voting system that perfectly translates the preferences of the electorate into a political outcome. That means every voting system will be flawed.

There are lots of good reasons to consider changing the UK’s system – we are something of an outlier in the democratic world – but advocates might find themselves having more success if they stop framing the choice as a matter of simple morality and start looking at the reasons “progressives” might oppose it.