It’s a highly unlikely storyline: in 1984, a group calling themselves Lesbians and Gays Support the Miners set about fundraising for strikers in a small Welsh mining village, overcoming local prejudice and defying media ridicule to form one of the most unlikely – and powerful – allegiances in the history of civil rights. Implausible, yes. Incredibly, it’s a true story.

Sensing that the plight of the striking miners (police harassment, media disdain, an affront to personal pride) reflected the struggles of the LGBT community, idealistic gay rights activist Mark Ashton (played by Ben Schnetzer) rallied a small group of friends to form a fundraising group called LGSM. When the unions refused to take their money, the group tracked down a remote pit village called Onllwyn in Wales which was deeply in need of support. Dai (Paddy Considine), the village miners’ grateful representative, then invited the group to drive down in their minibus and meet the bewildered miners in person.

The cast is a Who’s Who of great British drama. Imelda Staunton and Bill Nighy are compelling as dry-witted, kindhearted village elders Hefina and Cliff, while Dominic West excels as the outrageously camp Jonathan, whose flamboyant disco style wins over the village’s women and sees the dancefloor-shy miners lining up for lessons in the hope of wooing sexpot barmaid Debbie (Sophie Evans). After a string of high-profile TV roles, Faye Marsay makes her triumphant film debut as bolshy Northerner Steph and BAFTA-winning George Mackay shines as Joe, a Bromley boy from a homophobic middle-class family, taking his first intrepid steps outside of the closet.

The film does have its flaws: the script has a tendency to overstate the obvious and its characters are not particularly complex – some, like the broodingly malevolent Maureen (Lisa Palfrey) are drawn in such broad strokes that they feel almost cartoonish, while the unsympathetic depiction of tag-along lesbian couple Zoe (Jessie Cave) and Stella (Karina Fernandez) as shallow and unreasonable militant feminists makes for somewhat uncomfortable viewing.

But these niggles are outshone by the sheer exuberance of the film, which is so absorbing that the audience spent all 120 minutes alternating between laughter and tears before spontaneously breaking out in applause over the final credits. Outside of a smattering of festivals and screenings, this is the first time I’ve ever seen a cinema audience applaud a film (or seen so many people drying their eyes on the way out), and is testament to the craftsmanship of director Matthew Marchus as well as the quality of the performances. The heightened emotions and sense of solidarity in the audience adds another, powerful, dimension and means that this is a film that absolutely cries out to be seen at the cinema.

Pride is currently playing every day at the Cambridge Picturehouse Cinema, 38-39 St Andrew’s St, Cambridge CB2 3AR. Times and ticket prices vary – visit the website for details.