Staging an operatic rarity when the temperature outside the theatre is struggling to rise above zero is always going to be hazardous. English Touring Opera found this out the hard way with two of its male principals for Donizetti's 1836 L'assedio di Calais (The Siege of Calais) unable to perform for medical reasons.

So director James Conway mimed the role of Eustachio, leader of the Calais resistance to the invading Edward III, while Cozmin Sime not only sang the King in the first scene but then the taxing baritone part of Eustachio, the real hero of this story. Toby Girling substituted as Armando, one of the six men – including Eustachio and his son Aurelio (Helen Sherman) who volunteer to die that their city might be saved.

Yes, it's the story of the Burghers of Calais. Donizetti wrote it in three acts but Conway and musical director Jeremy Silver omit the third act, moving Eduardo's fireworks cavatina and cabaletto to the first scene and a major concerted number for those who will be left to survive to the second scene of the second act. Like many in the audience, I don't know the opera well enough to comment on this, but the music certainly has a grandeur one does not necessarily associate with Donizetti, and the finale of sacrifice works in dramatic terms.

Sime thoroughly deserved his applause; it would be interesting to hear him as Boccanegra, a role that he covers. Sherman makes a powerful Aurelio, effortlessly dominating in ensemble and giving ferocious weight to his/her arias. Another noteworthy voice is that of Paula Sides as Eleonora, Aurelio's wife and the mother of his son. A soprano with all the high notes, but properly weighted, and able to convey the pathos of the woman who is powerless to change fate.

This production has a timeless setting (Samal Blak) with visual references to the 1940s Stalingrad siege. These townfolk have all but given up hope of a future, any sort of future. If they escape rape, robbery, and wholesale slaughter, that might almost be enough. You can see why Piotr Lempa's agent provocateur, set on by Adam Tunnicliffe's Edmondo initially stirs up the crowd to mutiny. In such circumstances, a leader is always vulnerable.