What to watch for in Wakefield and Tiverton & Honiton results – and why swing matters

Even if the Conservatives hold on in Tiverton, a significant swing away would represent a major setback for Boris Johnson, as Sean O’Grady explains

Labour is eyeing victory in Wakefield (Getty)

Two by-elections on one evening is something of a treat for the political anorak community, but it looks to be a disappointing experience for the prime minister and those of his MPs seeking to continue their careers after the next election.

The first thing to watch for is swing, the measure of how far voters in Wakefield and Tiverton and Honiton respectively have changed their minds since the last general election. Much of this figure will reflect a “protest” among voters who will return to their older allegiances at the next election. Yet by-elections remain a valuable indicator of public sentiment, albeit a snapshot, and represent real votes rather than opinion polls.

In Wakefield, avoiding loss would be a great success for Boris Johnson, and a surprising one. It’s not unheard of for a governing party to retain one of its own seats – in fact, this government even gained a seat in Hartlepool – but opinion polls and the government’s well-known challenges mean its majority of 3,358 (7.5 per cent of the vote) is not safe enough to prevent an upset.