The whirligig of time, politics and technological change have conspired to render David Edgar's adaptation of Charles Dickens's Nickleby more relevant now than the Royal Shakespeare Company's fabulous staging in 1980.

Dickens's novel conjured up early Victorian England beset by industrial/social change and heartless capitalism, with which today's Britain suffers affinities. This vigorous production by Jonathan Church and Philip Franks, boasting the two-parted text pruned to six and a half hours, offers a feast of comic amusement in Part One, when Nicholas Nickleby and sister Kate struggle for financial survival.

The directors, though, soften the force and focus of Dickens's attack upon criminal financiers, marriage-makers and fraudsters.

Designer Simon Higlett surprisingly settles for a wholesome, not very functional, picture postcard London setting. David Yelland as the villainously complex Ralph Nickleby spins a nice line in pompous inhumanity without making him seem dangerous enough, while Pip Donaghy's doubling of sadistic Wackford Squeers and lecherous Sir Mulberry Hawk stints on sheer nastiness. The first part, whose narrative is embroidered with such a rich thread of comic-eccentric characters, works a delectable treat, although Daniel Weyman's pugilistic, distinctly wooden Nickleby fails to register the heights or depths of Nicholas's emotion. Even so the fine troupe of actors, who serve as storytellers and commentators on their own characters, beautifully maintain the balance between comedy and pathos.

These opposing modes are powerfully represented by David Dawson's superlative, self-harming, mentally compromised Smike and Tricia Kelly's comic triumph as Miss Knagg, that model of leering ingratiation and vindictiveness. Jane Bertish's double-act as sexually jealous Madame Manatalini and languid Mrs Wititterley, with Zoe Waites playing a wildly amorous Fanny Squeers, vamping Miss Snevellicci and wronged Madeline Bray display spectacular versatility.

The first part's hilarious climax, a happy-ending version of Romeo and Juliet, marks the high-point. The three- and-a-half-hour part two declines into extended dullness, with the Cheeryble brothers triumphing over Ralph to allow Nicholas, but not society, a feel-good, happy ending.

• Until 27 Jan (0844 482 5158). Both parts played Wed, Sat and Sundays.