ENGLISH PLAYWRIGHT Howard Barker is something of a conundrum. Although he is subjected to a combination of neglect and hostility by the English theatre establishment, his profoundly poetic, metaphorical tragedies (which he terms, collectively, the "Theatre of Catastrophe") are recognised internationally as great classical dramas.

As a forthcoming celebration of his work at the Royal Scottish Academy of Music and Drama (RSAMD) in Glasgow suggests, Barker is more revered in Scotland than in England, where he has not been produced by either the Royal Shakespeare Company or the National Theatre in more than a quarter of a century. In addition to staging the 1997 play Wounds To The Face, the RSAMD will host a symposium on the author's work, which will be attended by Barker himself.

The production of Wounds To The Face will be the 11th Barker play to be directed at the RSAMD by the Academy's head of acting, Hugh Hodgart. A drama that explores, deeply and dispassionately, the implications and meanings of the human face (through a series of incidents and processes, such as war wounding, ageing and plastic surgery), it is, Hodgart believes, a fine example of Barker's unique approach to theatre.

"In this play, there's the character of a soldier who's missing most of his face, because he lost it in an encounter with an exploding grenade," the director explains. "He is readopted by his mother and, ultimately, they swap faces. There aren't many plays where you see something like that happen, but once you embrace it, it's not a problem. I just wish there were more playwrights who had the nerve to imagine that kind of thing."

Hodgart's regard for Barker is shared widely in Scottish theatre. In recent years we have seen acclaimed productions of Barker's dramas Victory, at the Royal Lyceum, Edinburgh (directed by Kenny Ireland, a founder member of Barker's Wrestling School theatre company), and Scenes From An Execution, at Dundee Rep (directed by Dominic Hill, now director of Edinburgh's Traverse Theatre). One of Scotland's semi-professional companies has even got in on the act, with Strathclyde Theatre Group staging an impressive presentation of A Hard Heart.

For Dominic Hill, as for other admirers of Barker's theatre, the appeal of the plays lies precisely in those elements that people in English theatre, such as Trevor Nunn (former director of the National Theatre), find most distasteful. "Barker's uncomfortable," says Hill, "I heard a strange story about Trevor Nunn throwing Barker's play The Europeans across the room in outrage when he read it. Barker makes it hard for the audience, he makes us think uncomfortable things. Most theatre exists in order to reconfirm people's prejudices and their opinions about themselves, and he fights against that."

Barker's imaginative possibilities have gained him a great respect among actors, who tend to be invigorated by the challenge presented by his characters. Irene Macdougall, who played the role of the art critic Rivera in Hill's production of Scenes From An Execution, remembers: "When I played that character, I felt clever, quick, glassy. That is Barker's writing, not me. Barker excites the intellect and the imagination in a way very few other writers do. Although it is very clear what a character represents, there is a huge amount of freedom within that. Many clever writers keep you out. Barker, on the other hand, opens the door to his mind and invites you in, and asks you to explore. It is very moving and very exciting."

John Bett, who picked up the best actor award at the Critics' Awards for Theatre in Scotland for his portrayal of Urgentino in the same Dundee Rep production, agrees: "There is no small talk with Barker, it's right into the meat. It's about ideas, and it's very witty ... It's not an easy ride, you can't rest on your laurels, you have to engage. I personally find that very exciting, intellectually. You're not asked to do that very often."

If Barker's theatre offers richly rewarding characters to actors, his work is, Macdougall suggests, no less rewarding for audiences: "Experiencing a Barker play, your whole self becomes involved. I remember seeing The Europeans at the RSAMD for the first time, and it was like coming face to face with humanity at its best and worst. It was as if my head was bursting with so many ideas."

Those who revere Barker do so because of the boldness of his ideas and his resistance to a theatre that just offers the audience bland reassurances and warm entertainment (he calls such theatre "massage"). It is time, his admirers insist, for Barker to be recognised as a truly great theatrical author.

"I would easily compare him to the great writers, like Shakespeare, Wilde, Beckett and Pinter," says Hodgart. "We do Barker at the Academy for the same reason we do Shakespeare; he really delivers for the actors."

For Hill there is "no other contemporary playwright who has, over his career, created a type of theatre that is unique to them. He is one of the great makers of theatre. There are occasionally giants, like Bertolt Brecht, who stand up and do something with the form that changes the way people think about theatre. I think Barker is, undoubtedly, one of those people."

Wounds To The Face is at the RSAMD, Glasgow, May 20-24. Howard Barker will take part in the symposium, chaired by Mark Brown, at 4pm on May 24 at the RSAMD