Before Jacqui Smith’s husband started viewing adult entertainment, he would have done well to see this.

It illustrates that one should never mix sex and politics, particularly if the person in power has been on the moral high ground.

The once inflexibly-righteous Angelo (Jason Merrells) is charged with trying to restore order to Vienna by the Duke (Alistair McGowan), whose laxness has let it slide into turpitude. Angelo orders the execution of Claudio (Max Bennett) for making his girlfriend pregnant but when Claudio’s virtuous sister Isabella (Emma Lowndes) comes to plea for mercy, he agrees to grant it, only if she will sleep with him.

Isabella believes her brother would sooner die than see her so dishonoured. Claudio doesn’t see it the same way. The Duke, meanwhile, has disguised himself with a friar’s robes, a pair of glasses and a Scottish accent to watch the proceedings and meddle where necessary.

This is the last of Shakespeare’s comedies and quite possibly the grimmest. It is challenging, from the rapidity with which the Duke abandons his post, to the fact that he is trusting a man to be just whom he later reveals he knows to be flawed – after he rejected his fiancee when she lost her dowry. And if he was counting on this ruthlessness to clean up Vienna, then why try to stop him?

It also comes unstuck when marriage is used as punishment and reward in hasty couplings so that Shakespeare might secure an ‘all’s well ‘ending.

This is a solid production, directed by actor Jamie Glover. Merrells has a rigid piety as Angelo while McGowan, not unsurprisingly, taps into the humorous opportunites his role as the disguised Duke offers, particularly when having his ear bent about his failings by Lucio (an amusingly rakish Patrick Kennedy).

It has an austere look, the action played out against blackened brick walls and looming windows, but it all looks a little too well-tailored to really convince.

* Running time: 2hrs 45mins, until Saturday