A new record is about to be set for the longest period of time since a parliamentary by-election was held in the UK.

On March 5, a total of 582 days will have passed since voters last went to the polls in a Westminster by-election.

The gap is unprecedented in post-war history, according to analysis by the PA news agency.

The current record is 581 days, which was the period of time between the Ogmore by-election on February 14 2002 and the Brent East by-election on September 18 2003.

POLITICS ByElections
(PA Graphics)

Parliamentary by-elections are typically triggered by an MP resigning or passing away – but despite all that has happened in the past 19 months, including the coronavirus pandemic, no seats have fallen vacant.

The most recent contest in the UK took place on August 1 2019, when the Liberal Democrats gained the constituency of Brecon & Radnorshire from the Conservatives – only for the Conservatives to win it back four months later at the general election.

By-elections for seats in the House of Commons have long been a common feature of the political scene, delivering many a shock result, surprise defeat or stunning victory.

To go for more than a year-and-a-half without a single one of these contests is highly unusual, however.

Votes are taken from a ballot box during the count of votes in the Brecon and Radnorshire by-election in August 2019 (Ben Birchall/PA)
Votes are taken from a ballot box during the count of votes in the Brecon and Radnorshire by-election on August 1 2019 (Ben Birchall/PA)

Robert Ford, professor of political science at the University of Manchester, says several factors might be responsible for such a lengthy spell without by-elections.

“There has been a long-term trend towards them becoming less frequent, because of improving health and life expectancy in middle age,” he told the PA news agency.

“This will have had an impact, given that so many MPs, even today, remain men in their 40s through to their 60s, often not with the healthiest of lifestyles.

“But there has also been a more recent trend: a decline in political events that have triggered by-elections. In the past 10 years we had a lot of vacancies in parliament caused by resignation rather than death: MPs who resigned to run for Police and Crime Commissioners and for mayors, or who resigned because they didn’t agree with their party leader.

“Then at the 2019 election you had an unusually large turnover of MPs, both because of long-standing safe Labour seats falling, many of which had very elderly MPs – such as Dennis Skinner – and also because of a lot of retirements over Brexit, thanks to people who were expelled or resigned the whip. Many of those people were relatively veteran MPs as well.”

This kind of political turbulence appears to have come to an end – for the time being at least – thanks to another factor: Covid-19, which has “drastically decreased the kinds of political activity that might have triggered resignations and hence by-elections,” Professor Ford adds.

Since the end of the Second World War, the average number of UK parliamentary by-elections has declined from 11 per year in the 1950s and 60s – the equivalent of almost one a month – to three per year in the 2000s and four per year in the 2010s.

The longest gaps between by-elections have all occurred within the last 30 years: from November 7 1991 to May 6 1993 (546 days), from November 20 1997 to June 10 1999 (567 days); from February 14 2002 to September 18 2003 (581 days); and the current gap since August 1 2019.

A baker with a basket on his arm leaves a polling station in Towcester after voting in the South Northamptonshire by-election on November 22 1962 (PA)
A baker with a basket on his arm leaves a polling station in Towcester after voting in the South Northamptonshire by-election on November 22 1962 (PA)

“It’s a shame not to have them,” Professor Ford says of the current lack of by-elections, “as they have a rightfully treasured place in the British political culture. For reasons both good and bad, they are treated as barometers of parties’ national fortunes, but you also get wild-card elements of local politics – a local campaign that catches fire, or someone managing to ride a wave of anti-incumbent sentiment to win.”

For anyone feeling withdrawal symptoms at not having seen a ballot box for a long time, however, a bumper polling day is coming later in 2021 in the shape of “Super Thursday”.

Elections are due to take place on May 6 for the Scottish and Welsh parliaments, the London assembly, many local councils in England, 13 directly-elected mayors including London and Greater Manchester, and Police and Crime Commissioners in England and Wales.

The scale of Super Thursday means that every eligible voter in Great Britain will be able to cast a ballot in at least one type of contest.