ARDENT socialist J B Priestley might have been disappointed to learn that, 60 years since he wrote An Inspector Calls, audiences still have a lot to learn from this powerful modern morality play.

But, just as the social divisions and blinkered attitudes the playwright was thrusting into the spotlight are still more or less intact, so Priestley's beautifully direct appeal to our collective social conscience has lost none of its thought-provoking power.

The play opens with a mysterious police inspector, Goole (Nicholas Day), gatecrashing the engagement party being thrown by wealthy industrialist Birling (David Roper) - just as he is propounding his social theory that it is "every man for himself" in this world.

Alternately calm and boiling with anger, Goole brings shocking news - that a young woman has committed suicide by drinking detergent, and that each member of the family is in some way responsible for her taking her life.

With an ingenious set which sees the family at first suspended above, then later pitched into, the grimy, rain-lashed city streets, and shiveringly doom-laden music by Stephen Warbeck, this award-winning National Theatre production definitely stands up to inspection.