When the Liberal Democrats open the party conference season later this month in Bournemouth they will have good reason to feel they are on a high. This will not be because the party is gaining popular support. In August polls their average support was just below 11 percent, their lowest share of the national vote since 1970. But because the Liberal Democrat vote is now much more concentrated, it will more than double the number of seats they party would win if a general election were held today. Electoral Calculus forecasts a Liberal gain of 14 seats, and there is a one in ten chance that they could pick up as many as 38 additional seats. Either outcome would give the party their most MPs since 2010.
The Liberals appear to be flying high because the Conservative Party support is currently at a lower level than at any general election since before universal suffrage was introduced in 1918. National poll figures show Tory support is down by 17 percentage points since the last general election. Thus, all but one of the 38 seats that the Liberal Democrats may win is now held by the Conservatives. The other is a Scottish Nationalist seat.
None of the potential Liberal Democrat gains is now a Labour-held constituency. For example, in Sheffield Hallam, which in 2015 returned the party's leader, Nick Clegg, there is currently a seven percent swing to Labour from the Liberal Democrats. This pattern tends to be repeated in seats where Labour is the chief challenger to a Tory MP. Even though Labour and Liberal Democrat leaders are not promoting tactical voting to oust Conservative MPs, sufficient electors have twigged to the idea.
The forthcoming by-election in Mid-Bedfordshire will be a test of what happens if both opposition parties campaign hard to win votes. Labour's claim that it is best placed to take the seat because it is in second place is a half-truth. It trailed the Conservatives by 38 percent at the last general election. The Liberal Democrats can point to the fact that they had held the seat, even though this was only in 1929. Since two half-truths don't make a truth, the Tories can hope divisions among their opponents will work to their advantage.
Nationally the Conservatives are caught in a pincer movement. Of the 38 seats that are potential Liberal Democrat gains, 36 are in the South of England; the other two are suburban Manchester seats that the party had won not long ago. To stem the tide of Conservative defectors to the Liberal Democrats, Rishi Sunak would need to endorse more moderate views on issues such as immigration and the European Union. But this would cause trouble among the majority of his MPs. In the North of England constituencies that the Tories gained from ex-Labour voters, liberal values are not the issue; it is the cost of living and this is promising big gains for Labour there.
For Keir Starmer signs of a Liberal Democrat revival promise the best of both worlds. For a starter, every seat that the Liberal Democrats gain increases Labour's Westminster lead over the Conservatives. Moreover, on the basis of current polls, for every seat the Liberal Democrats gain, Labour is likely to gain 15 seats, enough to make Starmer secure in Downing Street without any need for a coalition pact.
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.