The Politics Shed- A Free Text Book for all students of Politics.
Under the current electoral system, Reform UK's seat share would surge, with its candidates winning a plurality of the vote across most English regions. Labour and the SNP would confirm their traditional dominance in London and Scotland respectively.
Under the current system, Reform could lead the next government, winning 46% of seats with only 28% of the vote. A Reform-Conservative coalition would claim a majority.
Reform would be the largest party in fractured parliament, and would be well short of a majority. A coalition would be inevitable, but either a leftwing or rightwing coalition would struggle to claim 50% of the seats.
How it works: Voters choose a party and seats are allocated in proportion to each party's vote share. Used widely across Europe and for Senedd elections in Wales, party list systems can use larger or smaller constituencies, balancing local representation against overall proportionality.
In a party list system, voters would be choosing a party – rather than a single candidate – in large regional constituencies. The higher proportionality produced by larger constituencies would result in a scaled-down SNP presence in Scotland, and a lower Reform seat share, closer to their national polling figures.
No single party would win a majority, and a coalition would be needed. While Reform would be the largest party, a leftwing coalition would be able to claim 52% of the seats.
How it works: Voters rank candidates by preference, with votes redistributed as candidates are elected or eliminated until all seats are filled. Used in Northern Ireland, the Republic of Ireland and Malta, it aims to balance local representation with proportionality through multi-member constituencies.
STV systems aim to produce proportional results while maintaining strong local representation. Voters would be ranking their favourite candidates in a number of subregional constituencies. STV would reduce the dominance of any one party in a region – for example the SNP in Scotland, Reform in the north-east or Labour in London – in favour of smaller parties.
Reform would win the largest share of the seats, with a third, but it would not be enough to form a government. A Reform-Conservative coalition would just claim a majority with 51% of seats.
How it works: Voters cast one vote for a local representative and one for a party. This gives a local constituency MP. Additional seats are then allocated regionally or nationally to make the overall result more proportional. Used in Scotland, Germany and New Zealand, the balance between constituency and list seats determines how proportional the outcome is.
AMS is a compromise solution that combines single-member, first-past-the-post constituencies with several regional top-up seats aimed at making the outcome of the FPTP vote more proportional. Strong local representation would be maintained, while ensuring that smaller parties such as the Greens get their fair share of seats even outside their traditional southeastern strongholds.