The message is clear: it's time to put first-past-the-post out to pasture

There is no avoiding it – the UK’s electoral process is well past its sell-by date. In 2010 the first-past-the-post system failed to deliver a single-party majority government and it is very unlikely to deliver a stable coalition government in 2015.

The problems of the first-past-the-post system go beyond the fact that Labour and the Conservatives are unable to secure a majority of seats in the House of Commons.

The two main parties are also in trouble because they will not be able to rely on the support of small parties like the Liberal Democrats, UKIP or the Greens to form a stable coalition government. If current polling projections are correct, none of the different permutations of coalition government will be able to command a majority in the House of Commons after May 7.

First past the post disproportionately discriminates against small parties (except the SNP which actually benefits from the current electoral system). It means that neither the Liberal Democrats, or the Greens or UKIP will have sufficient MPs to prop-up a Conservative or Labour-led coalition in 2015.

This is problematic because, though minority governments can last a full term they are less stable and can lead to permanent legislative deadlock.

Keeping up with the times

This state of affairs is the result of changes to the British party system that have been taking place since the 1970s. Where two parties once dominated, smaller alternatives have been emerging. For this reason, it is highly unlikely that an electorally diverse country like Britain will revert to the two-party politics of the post-war period in the near future.

Until 2010, the electoral system hid the multi-party nature of British politics (smaller parties and independent candidates attracted 30% of voting intentions but gained very few seats). In 2015 it is no longer possible to hide those changes. The only way out of this deadlock is to reform the electoral system.

Fortunately, the leaders of the main parties do not have to go far to find viable options that fit the requirements of Westminster politics. Two options – Alternative Vote Plus (AVP) or the Additional Member System (AMS) – have the potential to break the current electoral deadlock, albeit in a rather incremental manner.

Both have the potential to deliver slightly more proportional results while keeping some elements of the Westminster model (namely, by maintaining the link between MPs and their constituencies) alive.

How it works

The AVP is an electoral system proposed by Jenkins Commission in 1998. It was designed to meet the specific requirement of the Westminster system at the request of Tony Blair, but was never adopted.

The AVP system is mostly a majoritarian system with some elements of proportionality. Under this system, 75 to 85% of MPs would be elected by alternative vote (which means voters rank candidates in order of preference). The remaining 15 to 25% of MPs would be elected by a small top-up regional list to ensure that all parts of the UK are adequately represented.

FPTP favours the top two.Paul Morris, CC BY-SA

This system has the advantage of keeping the possibility of single party governments alive and of maintaining the link between MPs and constituencies, but would also deliver more proportional results for the smaller parties.

And because those smaller parties (including the three main parties in Scotland) would be able to win more seats, they could more readily form a two-party coalition government. Similarly, Labour and the Conservatives would be able to elect more MPs in Scotland – currently the first-past-the-post system exaggerates the popularity of the SNP.

The AMS, which is currently used in elections for the Scottish Parliament and the Welsh Assembly, delivers slightly more proportional results.

Like AVP, the AMS is based on voters casting votes for two types of MPs: one group elected by first-past-the-post and the other by a top-up regional list.

In elections for the Scottish Parliament – which, incidentally, have delivered coalition governments, a minority government and now single-party majority government – 73 of the 129 MSPs are elected by first-past-the-post voting and 56 by regional lists. In the elections to the House of Commons the percentage of MPs elected by regional lists can be calibrated to deliver the desired amount of proportionality to the electoral results.

They can handle it

In the past, these systems have been criticised for being too complicated. But Welsh and Scottish voters seem to have had no trouble in working around the two ballot papers.

They have also been attacked for creating two types of MPs. Again, this is a false criticism, as Westminster already produces two types of MPs: they are called frontbenchers and backbenchers.

The advantage of AMS or of AVP is that voters would no longer be sold the fiction that a member of government can also be an effective scrutiniser of legislation and a responsive constituency MP.

Sadly, neither Labour nor the Conservatives are contemplating electoral reform. Their manifestos are silent on this issue. But if in the past, both parties had good reasons to be cavalier about electoral reform, now it is actually in their interest to deliver it. It may be their only chance to lead a stable government, even if in coalition with other parties.