Sam Yates’s very fine revival of Irish Protestant playwright St John Ervine’s 1911 ‘Belfast tragedy’ Mixed Marriage (the first London revival in 90 years), set in pre-partisan Ireland, arrives at the same time as the BBC’s Mixed Britannia series of documentaries dealing with a very similar matter. Marriages between different religions can be fraught with difficulties, signifying a breaking away from tradition and potential children caught in the middle of two cultures. Polemic-heavy plays can be something of a chore, but this piece, despite not being particularly subtle and undeniably mouthpiece-heavy, combines an agonising domestic tragedy and a contemporary resonance that’s tragically all too recognisable in an urgent 80 minutes.

The drama takes place in the kitchen of the working-class Protestant Rainey family led by bullish patriarch John Rainey (a defiant Daragh O’Malley) and his kindly wife, where a portrait of the Protestant hero William of Orange takes pride of place. Their Catholic neighbours Michael O’Hara and Nora Murray are regular guests for tea. Being friendly with Catholics and uniting in a workers’ strike against the corrupt bosses (based on a real-life strike led by dockyard workers in 1907) is one thing for Mr Rainey, but the idea of elder son Hugh (Christopher Brandon) marrying the steadfast Nora (Nora-Jane Noone) is something else entirely, leading to familial warfare and a tirade of anti-Catholic sentiment.

Ervine’s writing has some lovely domestic details and he’s particularly good at highlighting the conflict between the microcosm and macrocosm, and the personal and the political. To Mrs Rainey, Hugh and Nora’s love is the ultimate symbol of a united Ireland, but to her husband, it’s a selfish act between two incompatible factions putting their personal desires before their faith. The idealistic but equally headstrong younger generation is represented by Michael (Damien Hannaway), who is supportive of Hugh and Nora’s romance, but is always in pursuit of the bigger picture, admitting that he would sacrifice his own family for Ireland.

The cast of six are all impressive, particularly Fiona Victory, who gives a performance to treasure as Mrs Rainey (Ervine’s own mouthpiece, perhaps?), a warm-hearted and outwardly conventional matriarch with a sharp mind of her own. This devoted wife and mother is unafraid to stand up to her husband and articulate her acute sense of what really matters, the running joke about the different roles of men and women in regard to the strike turning into something more profound.

Yates makes excellent use of the Finborough’s compact space, evoking a close sense of claustrophobia and shabbiness assisted by Richard Kent’s sepia-tinted design and David Plater’s lighting. Alex Baranowski’s immersive sound design echoes from all corners, heightening the sense of entrapment and the outside world beyond the Raineys’ kitchen, with Mr Rainey’s pre-recorded speeches effectively covering the transitions between scenes.

Inevitably, things don’t end well for the lovers caught up in forces beyond their control. Nora, having been cast as a temptress by her prospective father-in-law, takes the blame by casting herself as the sacrificial lamb. It’s hard to tell whether this act is supposed to be seen as noble or misguided. Ervine’s play remains a plaintive cry for understanding and compassion. It is a bleak picture of the premature judgement day that explodes into the kitchen when bitter, irrational grievances prevent two people in love from choosing their own lives.