Conventions are an important part of the UK constitution. However, as they are not codified, they can both develop and disappear. Some conventions take hold and become politically entrenched – for example the Salisbury Convention. However, others that may emerge may never take hold at all and the Carswell Convention is a good example of this.

What was the Carswell Convention?

From time to time in UK politics politicians ‘cross the floor’ and join other parties. There is nothing to stop them doing this at any time. Some famous examples of MPs who have crossed the floor include:

Winston Churchill – Undoubtedly the most famous MP to have ever crossed the floor. He left the Conservatives to join the Liberals in 1904 after opposing the Aliens Bill. He held a number of Cabinet positions as a Liberal before returning to the Conservatives in 1924.

Shaun Woodward – In 1999 Shaun Woodware defected from the Conservatives to Tony Blair’s Labour party after being sacked from the Conservative frontbench. He moved to a Labour safe seat and remained a Labour MP until 2015.

Quentin Davies – In 2007 Quentin Davies left David Cameron’s Conservatives for Labour saying that under Cameron the Conservatives did not stand for anything.

In August 2014 Douglas Carswell, a strongly Eurosceptic Conservative MP, dramatically decided to leave the Conservative Party and join UKIP:

However, rather than cross the floor in the traditional sense he announced that he would resign as an MP thereby forcing a by-election that he would then stand in as a UKIP candidate. This would give his constituents the chance to give their view of whether or not they agreed with his decision to leave the Conservatives and join UKIP. Carswell comfortably won the by-election and therefore became UKIP’s first ever MP.

Following this another Conservative MP decided to leave the party and join UKIP. Just like Carswell, Mark Reckless resigned his seat and forced a by-election, which he also won:

As such, it appeared that a new convention may be establishing itself in British Politics whereby if an MP wanted to move parties then they should seek the consent of their constituents by forcing a by-election.

How did Change UK show the convention had not taken hold?

Following the EU Referendum in 2016 British political parties became splintered by the issue of Brexit. There were suspicions that a new centrist political party was needed and on the 18th February 2019 seven Labour MPs resigned and formed the new ‘Independent Group’. Two days later the group were joined by three Conservative MPs: Anna Soubry, Sarah Wollaston and Heidi Allen.

In April the new group registered a a new political party called Change UK. However, unlike in the case of Carswell and Reckless, none of their MPs saw a new mandate from their constituents by forcing a by-election. Given the precedent being set by Carswell and Reckless, many MPs were critical of this decision:

” If you splinter of and are going to another political platform have a responsibility to go back to the electorate”

Then Shadow Chancellor John McDonnell

When the General Election took place in 2019 every single Change UK MP lost their seat with the party receiving just 10,006 nationally, just 300 more than the Monster Raving Looney Party.

In 2022 Christian Wakeford crossed the floor to leave the Conservatives and join Labour. There were were demands from around the chamber that he resign and force a by-election – clearly indicating the clamour for such a move has largely passed. If Change UK had acted differently in the period before the General Election in 2019 then an emerging convention may have become more politically entrenched. As it is, it was allowed to die a quite death.

What attempts have been made to codify this issue?

There have two attempts in the past to codify this issue, however, both have come through Ten Minute Rule Motions and are therefore unlikely to succeed. In 2011 Conservative MP Chris Skidmore introduced a motion forcing a by-election for any MP who changed parties but it did not reach a Second Reading. In 2021 Conservative MP Anthony Magnall introduced a similar motion, but again this did not reach Second Reading.

Article Summary

The Carswell Convention appeared to be a new constitutional convention that may take hold in the UK. However, this was short-lived and MPs can still change parties without having to hold a by-election to check the view of their constituents on their decision.

Key Terms

Carswell Convention – A convention that never fully emerged that indicated an MP that crossed the floor should resign and force a by-election.

Crossing the Floor – The term for an MP moving from one party in Parliament to another.

Change UK – A short-lived centrist political that emerged in 2019 but was dissolved following the 2019 General Election.