This year's winner of the continent's premier drama award, the Europe Theatre Prize, is the eminent French actor and director of a zillion plays and operas, Patrice Chereau. For me, though, it was a tiny company from Belarus that stole the show during the theatrical festivities that have been held in Thessaloniki over the past few days. They and their friends have been harrassed, arrested, jailed, beaten up, deprived of any day jobs they've got - and still they managed to travel to northern Greece with a new show that has tough things to say about the dictatorship under which they precariously subsist.

Belarus Free Theatre paid a brief visit to London in February - minus two actors prevented from travelling by the Belarus authorities - with the two plays that led Vaclav Havel, Tom Stoppard and Harold Pinter to nominate them for the special award they've just received from the Europe Prize's jury.

Both Generation Jeans and Being Harold Pinter, as the pieces are called, were restaged in Thessaloniki and each proved well worth seeing anew. The first, a monologue delivered by one of the company's founders, Nikolai Khalezin, starts by remembering how jeans were a symbol of freedom and defiance ("a little bit of America and Britain") under the Soviet regime and goes on to evoke the degradation and imprisonment he and others have suffered under the authoritarian rule of Alexander Lukashenko. The second skilfully uses extracts from Pinter's writings, from The Homecoming in 1965 to Ashes to Ashes in 1996 to his Nobel acceptance speech in 2006, to expose the repression and brutality to be found in Belarus and elsewhere.

The new show, The Silent Zone, is a bit fragmentary and needs cutting, yet still packs a punch. It begins with the actors recalling their often painful childhoods; it continues with portraits of people on the margins of Belarus society, such as the gay black man who deals daily with homophobia, racism and violence and an alcoholic so chaotic she didn't know she was pregnant until she delivered a child; and then it explodes into life with the third act the company calls Numbers. This opens with an exemplary peasant emerging from a suitcase and dancing merrily round the stage, only to present us with a series of harsh images and harsher statistics. For instance, an actor dangles a fishing rod above his colleagues, who then fight like piranhas for the bait on its hook: unsurprising, perhaps, in a country where the surtitles tell us that salaries average some $250 a year.

Since the company also comes up with other damning numbers, for instance that Belarus is among the nations that rate highest for suicides and the lowest for press freedom, one fears for its actors' safety when they return home to Minsk. There, they perform in the samizdat style practised by Havel in Soviet-bloc Czechoslovakia. People phone a company contact for a play that may not necessarily be particularly political. She organises a secret meeting-point for them and others, in one case in a local cemetery. And they end up performing in some small, obscure space, maybe a cafe or someone's living room. But this is dangerous not just for them but for their audiences. As they told a press conference in Thessaloniki, one supporter was warned he'd lose his business if he made contact with the Free Theatre again - and others have been intimidated with threats involving their children's education.

But the new play's title is pointed. This company is determined that Belarus shouldn't remain a "silent zone" of fearful people, menaced by their own regime and ignored by the world outside. In Thessaloniki they quoted Havel, who told them "you need to talk loudly, openly and honestly. It's the only way to stop dictatorship. If you keep silent, that dictatorship will be prolonged because nobody will pay attention to your country." And that's what they're doing, talking candidly and internationally, with the hope that was movingly evoked at the awards ceremony itself.

They stood there, a clutch of performers with their children in tow and unfurled a European Union flag with the single word "Belarus" inside its circle of stars. We may have our suspicions of the EU, but then we're a privileged nation that takes its international status for granted. These Belarusians simply want to be normal Europeans - free to come, free to go, free to belong, and free to say what they want where they want and to whom they want.

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