Brecon showed what can happen when Remain parties unite. Could the tactic see Boris beaten at a general election?

Inside Westminster: With the threat of a ‘regressive’ alliance between Johnson and Farage, a Remain pact is all the more pressing

The Remain movement is alive and kicking; reports of its death after Boris Johnson’s arrival in Downing Street were greatly exaggerated. The Liberal Democrats owed their victory in Thursday’s by-election in Brecon and Radnorshire to a Remain alliance in which the Greens and Plaid Cymru stood aside.

The result should give Johnson pause for thought about an early general election, at least before he has “delivered Brexit”. The Lib Dems have momentum under their new leader Jo Swinson and on present form, could increase their 13 seats close to their high watermark of 62 MPs in 2005.

Brecon showing the Lib Dems can win in areas where they have traditionally been strong is ominous for the Tories, who won an overall majority in 2015 by seizing Lib Dem strongholds in the southwest. Boris’s drive towards the no-deal cliff risks writing off the estimated 4 million 2016 Remainers who backed the Tories in 2017.