Conservatives accused of trying to 'rig next election' as analysis shows boundary changes will disproportionately benefit them

Proposed redrawing exercise would see Conservatives win 40 more seats than Labour even if they got identical number of votes, study finds

The Conservatives have been accused of “trying to rig the next election” after new analysis found that planned changes to parliamentary constituency boundaries would disproportionally benefit the Tories if both main parties won the same number of votes.

The proposed changes to constituencies across the UK would see the Tories win 40 more seats than Labour if they had an identical vote share, according to analysis by Electoral Calculus and PoliticalBetting.com.

The government plans to reduce the number of parliamentary constituencies from 650 to 600, saying this will make elections fairer by ensuring that each constituency contains a similar number of voters.

However, the finding that the changes would most benefit the Conservatives prompted accusations that the government is “gerrymandering”.

Recent polls put both Labour and the Conservatives on 38 per cent, with the Liberal Democrats on 10 per cent. If those numbers were replicated at a general election based on the new constituency boundaries, the Conservatives would gain 285 seats (43 per cent of the total) to Labour’s 245 (38 per cent). The Lib Dems would win 14 seats.

Without the changes, the same vote shares would give the Tories 21 seats more than Labour, meaning the boundary changes could double the Conservatives’ advantage over their main opponents.

Electoral reform campaigners said the findings exposed the problems with the UK’s first-past-the-post voting system and called for the introduction of proportional representation.

Labour is opposed to the government’s boundary changes but does not support reform of the voting system.

Joe Sousek, a spokesperson for the Make Votes Matter campaign and executive member of the Labour Campaign for Electoral Reform, said: “These findings are grossly unfair because the number of seats each party wins has little relation to the number of votes they receive.

“Ironically, this is something the Labour Party cannot call out – because of its tacit support for our disproportional first-past-the-post voting system. It’s time Labour committed to proportional representation so seats match votes and elections are decided by the voters, not by the lines drawn on the constituency map.”

Tom Copley, a Labour London Assembly Member who backs electoral reform, said: “This is pure gerrymandering. The Tories are trying to rig the next election. What we really need is proportional representation to make sure a party’s share of seats reflects its share of the vote.”

Cat Smith, Labour’s shadow minister for voter engagement and youth affairs, said: “The boundary review as it currently stands is completely undemocratic, seeking to strengthen the power of the executive at the expense of backbenchers.

“If Theresa May was serious about reducing the cost of politics, she would stop stuffing the House of Lords.

“Labour stands ready to work with all parties to ensure that a boundary review can go ahead in a way that benefits our democracy, not just the Conservative Party.”

Under the new boundaries, a number of senior Conservatives face losing their seat if the 2017 vote share is replicated at the next election.

Labour would likely gain Hastings and Rye from former home secretary Amber Rudd, as well as the Chingford seat of former Tory leader Iain Duncan Smith.

Former chancellor Ken Clarke would also lose his Rushcliffe seat to Labour, while former London mayoral candidate Zac Goldsmith, the MP for Richmond Park, would see his taken by the Lib Dems.

The Boundary Commission’s final recommendations will be presented in the autumn and will then be voted on by MPs. The government is expected to try to push the changes through well before the next general election.​

A Cabinet Office spokesperson said: “The independent and impartial Boundary Commissions are currently undertaking this review, as laid out in primary legislation passed by Parliament. The boundary review is designed to ensure equally sized constituencies based on up-to-date demographic data.”