First look at new cast for Last Tango in Halifax series 4

Sex Education's Lu Corfield, Anna Leong Brophy (EastEnders), Noorul Choudhury (Ackley Bridge) and Liam McCheyne (The Bay) have all signed on for the series.

They join returning castmembers Nicola Walker, Sarah Lancashire, Timothy West and Tony Gardner.

The casting news comes with our first bit of plot info for the series, which has been off the air since the 2016 Christmas special.

"Alan and Celia are now seven years into their marriage but, having moved into a desirable bungalow with stunning views across the Calder Valley, they aren't quite seeing eye to eye," a plot summary from the BBC reads.

"It isn't just their differing politics that's a source of tension; Alan's new supermarket job brings an unexpected challenge in the form of a wild local lad, and at Far Slack Farm Gillian faces trouble with a giraffe."

Meanwhile, Alan's brother Ted has come over on holiday from New Zealand with a surprise guest, and Caroline has found herself entangled in an emotional debacle at work.

"Yet again the entire Last Tango cast has proved to be so wonderful together, so uplifting, heart-warming, touching and funny, as they explore Celia and Alan’s relationship further, under the brilliant breath of fresh air that Gareth Bryn’s direction has given them," writer Sally Wainwright said.

BBC Director of Content Charlotte Moore previously confirmed exclusively to Radio Times that Last Tango will return for a four-part series in 2020.