Large gap between vote share and MPs hits Reform and Greens

The UK held a national referendum on reform of the voting system in 2011 after the 2010 election delivered a hung parliament and the Conservatives entered a formal coalition with the Liberal Democrats.

The proposal to replace the current first-past-the post system with an “Alternative Vote”, which advocates said would make results more proportional to the national share of votes cast, was rejected by the public, by 68% to 32%.

The referendum was the price exacted by the Lib Dems for entering coalition with the Conservatives.

Despite his party doing better under the current system than in previous elections, the Lib Dem leader Sir Ed said on Friday morning that he felt the British political system was “still broken” and would continue to support electoral reform.

Though this is the most extreme difference between vote and seat shares seen across the whole of the UK and in England for over a century, other nations of the UK have seen more extreme cases in recent history.

In the 2015 general election, the Scottish National Party took half of the votes and 95% of the seats in Scotland – a gap of 45 points between the vote and seat share.

The highest gap recorded in Wales was in the 2001 general election when Labour won just under half of the votes and 85% of Welsh seats in Westminster.

The Electoral Reform Society used more complex statistical scoring systems to compare the 2024 election result to others in UK history, but also concluded it was the most disproportionate on record.

Additional reporting by Robert Cuffe and the data journalism team.