If The Split offers up a true reflection of modern London, then just about everybody is getting divorced or seeking a pre-nup or about to break up or wishing they had chosen to spend their life with someone else. Thankfully, modern London is also home to the reputable Defoe firm, a company of divorce lawyers now run by the matriarch Ruth (Deborah Findlay) whose husband Oscar (Anthony Head) is creaking back onto the scene having left the family home 30 years ago, abandoning his wife and daughters.

The middle daughter, Nina (Annabel Scholey) works for Defoe, while the eldest, Hannah (Nicola Walker) has jumped ship to join another law firm, and as a result is often facing a member of her family across a negotiating table. To make matters yet more complicated, one of Hannah's new colleagues is an old flame who is now trying to date Nina.

This is only scratching the surface of the web-like inter-connectedness going on in The Split, and the sheer volume of complex relations may have been why creator Abi Morgan has chosen to keep the dialogue largely flat and simple: one character even quotes the ubiquitous line about murderers getting less time in prison than most unhappy spouses last in their failing marriage as if it's the first time we've heard it.

Hannah's husband Nathan (Stephen Mangan) is virtually the only male to come out of this show with any semblance of decency but that seems partly down to him being boring and reliable; the only time he threatens to display a bit of fire in the belly is when his kids are unable to name all of Henry VIII's wives.

Cutting through the labyrinths is the always superb Nicola Walker, who last worked with Morgan on the excellent River. Her every movement, gesture and expression is a masterclass in playing someone who is on the verge of losing it, but knows everyone is relying on her to hold things together. Whether her performance is enough to keep viewers ploughing through this convoluted stramash is another story.

Episodes watched: one and two of six

The Split starts on BBC One, Tue 24 Apr, 9pm.