TO TV audiences, Scottish actor Paul Higgins is the hilariously foul-mouthed spin doctor Jamie McDonald in the BBC sitcom The Thick Of It. Theatregoers know him as both the intimidated writer and the sarcastic sergeant in the National Theatre of Scotland's hit show Black Watch.

There is, however, more to the Lanarkshire-born actor than his acclaimed performances on screen and stage. When he's not acting, Higgins is often writing.

In 2008, his dark comedy Nobody Will Ever Forgive Us was staged at the Traverse Theatre in Edinburgh. His latest project, a musical play entitled The Choir, is a new departure.

Co-written with Ricky Ross of Deacon Blue fame, it takes us into the world of a community choir in Higgins's old stomping ground of Wishaw. The play, which is directed by Dominic Hill, artistic director of Glasgow's Citizens Theatre, opened in preview at the Clydeside playhouse last night.

For Higgins, a choir is an ideal environment in which to explore the desire of many people to resist the atomisation of modern life. "It's about people who want to have a sense of community," he explains. "They come together because they want to feel some sense of togetherness. However, their differences mean that this becomes very difficult."

The play's characters, who include an Iraqi doctor who works at Wishaw General Hospital and a Tory Party councillor, range in age from 19 to someone in their late-60s. The diversity of the group is, the writer says, the basis of the drama. "These people would never be in the same room if it wasn't for the choir."

Higgins is interested in how the differences within such a varied group of people can lead to unexpected moments of conflict. He is not, he says, in the business of creating "goodies and baddies".

"Good people can fall into conflict with each other," he continues. "It was very important to me that I don't take sides. "I don't favour one character over another. I wasn't going to make the Tory councillor some grasping, hard-right caricature, for example."

Incidentally, if you think it's a bit far-fetched that a community choir in Wishaw would have a Conservative councillor as a member, Higgins is keen to point out that the character is actually from Bothwell. "They do have Tory councillors in Bothwell," he says, "I checked."

If the play promises a nuanced approach to characterisation, it also seems set to defy expectations of musical theatre. As in Lee Hall's stage musical Our Ladies Of Perpetual Succour, which the National Theatre of Scotland premiered in August, the characters in Higgins's piece will only sing when they would sing in real life.

"It's not a conventional musical," Higgins insists. "It's not people bursting into song in the supermarket and other people can't hear them."

Nor, the writer adds, does the play feed into the current fashion for competitive singing. "It's not Gareth Malone's The Choir, much as I love that. These people are not getting ready for a competition. This is for themselves and for each other."

Much of the drama of the piece, Higgins explains, comes from the music itself. The choir is trying to build a repertoire based upon songs brought to the group by its members.

"Somebody will bring a song thinking, 'It's just a song', but to somebody else it's actually offensive. The politics of the play come out of that."

It's important to the writer that the tensions of the piece come from within the choir itself. "I didn't want any drama coming in from outside, with some external event that impacts on the choir. The drama just comes out of the fact that it's hard for 12 people to be in a room for long periods of time, talking about themselves and what's important to them."

What of co-authoring the piece with Ross, who has written the music and worked on the lyrics with Higgins? It was, says the actor-turned-writer, a strange and ironic experience.

"I started writing out of a desire not to collaborate, to do my own thing," he says. "It was a way of having something to do which I was in charge of."

Writing with someone else was, he admits, "the tricky bit". However, the collaboration with Ross has, ultimately, been a fruitful one.

The Deacon Blue frontman has, Higgins says, brought his wealth of experience to the project, helping him turn his ideas into singable songs.

He is equally happy with the cast of 12 actors that director Hill has assembled. "There's some talent in that room, in terms of the singing, the acting and the musicianship."

The result of all this collaboration, he hopes, is a production that will repay the faith of both the Citizens Theatre and its big-money co-producer Ambassador Theatre Group (ATG).

Originally, Higgins wrote the play for eight characters. He was astonished when ATG asked him to increase it to 12.

"They've been great", he says of ATG. "They've been incredibly supportive. They've helped out, but they haven't interfered in any way."

If the initial Glasgow run proves a success, there is a very real prospect that ATG will transfer The Choir to London and/or take it on a UK-wide tour.

"The whole thing is very exciting, and nerve-wracking as well," Higgins acknowledges. "It's a big deal."

The Choir plays the Citizens Theatre, Glasgow until November 14