PARK CITY, Utah  - A tense thriller about a mother deeply entrenched in the IRA and forced to choose between the organisation and the family she loves has earned high praise among the foreign films at this week’s Sundance Film festival.

“Shadow Dancer,” set against a backdrop of a Northern Ireland in transition, gave the festival a lift after it premiered earlier this week following some of the higher-profile U.S. fiction films that have failed to live up to pre-festival hype.

The film stars Andrea Riseborough as a Belfast mother who, along with two of her brothers, is active in the Irish Republican Army when she gets offered a deal by an British intelligence officer (Clive Owen) to turn against her colleagues and become an informant or else go to prison.

James Marsh, who made Oscar-winning documentary “Man On Wire,” directed “Shadow Dancer” which 1990s Northern Ireland TV correspondent Tom Bradby adapted from his book of the same name. Marsh said he was initially reluctant to work on the movie but ultimately won over by the idea of telling a more personal story of the conflict.

“In Britain you have this sort of exhausted sense of the Northern Irish troubles,” he told Reuters. “But I quickly got caught up in the premise of the story where you take a young single mother and you go and force her to spy on her own family. It’s an impossible bargain.” The moral quandary of Riseborough’s character — choosing between loved ones and dealing with the guilt of betrayal — are themes most audiences could relate to, said Marsh. Marsh applauded other films such as 2002’s “Bloody Sunday” that captured a particular episode of the Northern Ireland conflict, but said he was more interested in the microcosm of one family’s turmoil and how it reflected the region’s larger troubles.

“We didn’t try and bring in the bigger political story or the facts involved in this conflict. It felt like a very boiled down family thriller,” he said, adding he was not interested in getting “flashy and flamboyant.”

His restrained style has been lavished with praise. The Hollywood Reporter hailed his “carefully crafted” film, while The Guardian called it “a poetic and unapologetically arthouse story of betrayal and loyalty that, with its terrific score, measured pacing and fierce female performances, is a raw reminder of a sad and painful past.” Working alongside a support cast of Irish actors, the English-born Owen agreed only at the last minute to take the role, while American actress Gillian Anderson turns up in an unrecognizable role as Owen’s frosty British boss.

In the main role is English-born Riseborough, 30, who was recently seen playing Wallis Simpson in Madonna’s “W.E.” Marsh said she was partly cast due to her turns as “a surprising actress, every role she did, you didn’t quite recognize her.”