(Ustinov Studio till April 27)

THREE generations of the Coleman family live a chaotic and poverty-stricken life together in a home decorated in riotous browns – relying on Granny to hold everything together.

But when Granny falls ill, what will happen to the rest of the dysfunctional clan?

This is the premise of The Omission of the Family Coleman, the latest UK premiere in the Ustinov Studio, in Bath, an absurd comedy by Argentinian writer Claudio Tolcachir, in a new version by award-winning writer Stella Feehily.

I will declare from the outset - it’s one of the best performances I have seen in more decades of theatre-going than I could care to admit. Compelling, brilliantly performed, touching, painful, and darkly comic, this is an extraordinary production of a powerfully written play.

The Argentinian setting has been relocated to the Republic of Ireland, with Anne Kent (Coronation Street, Foyle’s War) as Granny, David Crowley (Origin, Ripper Street) as Damian, Evanna Lynch (Luna Lovegood in the Harry Potter films) as Gaby, Laoisha O’Callaghan as Mary and Rowan Polonski as Marko.

At the outset, it’s a challenge working out exactly how the characters are all related as Mary, mother to Marko, Damian and Gaby, seems less mature than her daughter and they live in a tumble of conflict, argument, affection and actual physical fighting.

But be patient. Gradually the characters come into focus: Gaby is a hard worker organising the washing and keen to earn money making clothes; surly Damian is fond of his Granny but involved in some dodgy dealing; their mother Mary is emotionally unstable and incapable of running her life; Marko is unpredictable and ‘difficult to manage’, being impulsive but also oddly insightful.

Enter Veronica, a fourth child, the one who grew up with her father and has a superficially successful life with money, marriage and a career – and the precarious balance starts to teeter. Then Granny is taken to hospital and with the lynchpin gone, everything begins to fall apart.

The performances are all excellent but the stand-out is Polonski as Marko - his portrayal is utterly convincing – every gesture, expression, every line he delivers.

Expertly directed by Laurence Boswell, this performance does not miss a beat.