TV tonight: Steve Coogan and Harriet Walter go head to head as Walden and Thatcher

Brian and Maggie

9pm, Channel 4

James Graham’s new drama questions the blurred lines between journalist and politician with this two-parter about one of the most famous political interviews of all time: Labour MP turned TV journalist Brian Walden (Steve Coogan) and prime minister Margaret Thatcher (Harriet Walter) in 1989. It begins by rewinding to when the two first met and formed an unlikely and unwise friendship. When Thatcher wins election, she starts to regret sharing too much with him. Hollie Richardson

Kirstie and Phil’s Love It or List It

8pm, Channel 4

The seemingly indestructible Allsopp and Spencer real estate enterprise rolls on, showing as little sign of slowing down as the UK’s housing market. This time, the pair step into the middle of a domestic argument in Hamilton. Scott and Jaqui’s kids have flown the nest, but the couple can’t agree about their next step. Phil Harrison

Idris Elba: Our Knife Crime Crisis

9pm, BBC One

Man on a mission … Idris Elba in Our Knife Crime Crisis. Photograph: 22 Summers/BBC

Last year, an average of four people a week were stabbed to death in the UK. “I nearly got two pulled out on me this week,” says 16-year-old Jayden, one of the people behind the statistics to whom Idris Elba speaks in this documentary. It follows the actor’s campaign to end knife crime, including discussions with the king and Keir Starmer. HR

Murder Trial: The Girl in the River

9pm, BBC Two

Until 2023, the murder of 14-year-old Caroline Glachan in 1996 was one of the UK’s biggest cold cases. This two-part series takes place inside the courtroom as three suspects stand trial two decades after Glachan’s body was found. It speaks to her mother, Margaret McKeich, who has kept fighting for the truth. HR

Grantchester

9pm, ITV1

Deliciously droll … Richard Goulding and Marianne Oldham as Lord and Lady Marwood. Photograph: JF/ITV

A droll episode with a delicious setup: Alphy (Rishi Nair) visits a dysfunctional manor house. It’s a shame when a workaday murder intrudes on the barbed interplay between dishy Alphy, a bigoted weakling of a lord (Richard Goulding) and a dangerously randy lady (Marianne Oldham). Jack Seale

The Cockfields

10pm, BBC Two

Joe Wilkinson’s and Dave Earl’s midlife sitcom first aired on U&Gold; now, it has found a primetime spot in which to replay. Wilkinson plays Simon, who heads back to see his family on the Isle of Wight with his girlfriend Donna (Diane Morgan) for his 40th birthday celebrations – and an eventful weekend ensues. HR

Live sport

Champions League football 7pm, TNT Sports 1. Aston Villa v Celtic (kick-off 8pm). Manchester City v Club Brugge is on TNT Sports 2, PSV Eindhoven v Liverpool on TNT Sports 3 and Girona v Arsenal on TNT Sports 4 (all 7.30pm).