A by-election is on the cards for Rutherglen and Hamilton West, after former SNP MP Margaret Ferrier was recalled by her constituents. She'd flouted lockdown rules in 2020, taking a train from London to Scotland despite testing positive for Covid. Given that Labour will need to make gains in Scotland in order to win the next election, this by-election has become a bellwether for the party. Cindy Yu talks to Katy Balls and Lucy Dunn about what to expect.

Produced by Cindy Yu.