The Labour Party now has an 87 percent likelihood of taking control of British government according to the latest Electoral Calculus poll-of-polls which shows the Conservative Party favoured by less than one-third of voters. Keir Starmer could enter Downing Street through the front door by winning an absolute parliamentary majority or just as likely by the side door as leader of a minority government.
The central prediction of Electoral Calculus leaves Keir Starmer 18 seats short of a parliamentary majority. This is sufficient to take control of government because the Conservatives would be 79 seats short of a majority.
If Labour won 308 seats it could take office with the support of the Liberal Democrats and Plaid Cymru. The Liberal Democrats would be in a weak position to demand seats in a coalition government if they had only 11 seats. The best forecast of gains leaves the Liberal Democrats with more seats but less influence on government because it would be due to an anti-Conservative landslide simultaneously delivering a Labour majority.
Even if Labour were 20 seats behind the Conservatives, it could still form a government by making a pact with the Scottish National Party, once again on course to be the third largest party in the House of Commons. The SNP has a clear price for its support: authorisation of a referendum on Scottish independence. Labour favours maintaining the Union, but a referendum would guarantee Labour two years in charge of the UK government while a bill proceeded through Parliament and a referendum was organised in Scotland.
Current polls give the Conservatives a one-in-six chance of winning the most seats in the Commons but not an absolute majority. To prevent Labour forming a government, the Conservatives would need to assemble a kaleidoscopic coalition including the Scottish National Party, Plaid Cymru, the Ulster Unionists and the Liberal Democrats. Doing so would be unlikely to produce a Conservative government because these parties do not want to work with a Conservative government. A Parliament in which no government could be formed would trigger a second general election.
If a general election were held now, last month's polls give the Conservatives only a seven percent chance of winning the majority needed to secure another term of office. This is an incentive for Conservatives to be glad that a general election does not have to be held until December 2024.
Supporters of the Prime Minister can cite evidence showing a mid-term slump in government support is normal. They can take comfort too in the Liberal Democrats' problem of translating by-election support into winning dozens of seats at a general election. Moreover, Labour's support today is less than the party polled under Jeremy Corbyn's leadership in the 2017 general election. But Conservative MPs who still fear losing their seats as well as control of government can consider an alternative electoral strategy: triggering a Conservative leadership contest.
Richard Rose is Britain's senior psephologist and an expert on party government. His new book 'How Sick is British Democracy?: a Clinical Analysis' is published by Palgrave.