As the National Theatre careers from one disaster to another, WOS correspondent Mark Shenton reports on how the NT got itself into a hole and wonders whether it can get itself back out.

The Royal National Theatre of Great Britain has quite a weight to carry just in the baggage of its name alone. As our leading subsidised company, it is (or should be) the flagship theatrical institution of the UK - the one that promises excellence as well as choice, that entertains as well as educates, that provokes as well as pleases, that leads rather than follows. In short, it has to be all things theatrical to all men (and women) - a tall, even impossible, order, while also seeking to fill over 2,300 seats per night.

And the responsibility for maintaining these objectives is vested, ultimately, in one man (or woman, though that is yet to happen there): the artistic director. Lately, the current incumbent, Trevor Nunn, has been coming under sustained attack for his stewardship of the theatre, with many media and industry commentators now wondering aloud whether his contract to run it ought to be extended, as he apparently wishes it be, beyond its current tenure.

A populist summer season that kicked off with a damp and dire (but commercially successful) transfer of a regional production of the screen musical Singin' in the Rain - and is now set to return to the South Bank for Christmas - was followed by the London premiere of two complementary Alan Ayckbourn comedies, House and Garden. Also originally seen regionally, at Ayckbourn's home theatres in Scarborough, the National provided a logistical, if not necessarily logical, home for their London showing, since their performance (by the same cast in two theatres simultaneously) required a building that has two adjoining auditoria of sufficient size. Not that anyone any longer disputes that the National should be doing the work of Britain's most prolific, and popular, playwright - Ayckbourn s work has been a staple since Peter Hall first produced his Bedroom Farce on the South Bank. But these commercial comedies might, logistics aside, have been more suitable for West End production.

Roll on the winter, and yet another comedy that really belongs in the commercial sector has taken over the Lyttelton - a revival of Michael Frayn s Noises Off, which was a long-running West End hit when it was first seen at the Savoy 20 years ago. Meanwhile, in the Olivier, the more adventurous return to the notion of setting up a permanent acting ensemble (with which Nunn and John Caird had a great success last year) to present more serious fare has been derailed by problems with the directors Nunn brought in to stage the opening productions, Romeo and Juliet and Peer Gynt.

It was widely reported that Nunn himself took over the direction of Romeo and Juliet from the originally billed Tim Supple in the run-up to a postponed opening night, but it was obviously a case of trying to catch the horse after the stable door had been left unbolted. Nunn was lumbered with an inappropriate physical production and a concept that put it beyond repair. If it was all eerily reminiscent of the National's disastrous production of The Villains' Opera from earlier this year, that isn't too surprising given that Supple also directed that. It beggars belief, never mind The Beggar's Opera upon which the earlier show was based, that having allowed Supple to produce one catastrophe on the Olivier stage, Nunn then allowed him to start producing another. And worse, to utterly repeat himself in the process. With its over-emphatic use of a dismal musical soundtrack, and racially divided groups of gangland Londoners once again at war, Romeo and Juliet looked and sounded like the same show.

Peer Gynt, meanwhile, has also had to postpone its opening and has lost a number of performances on the way owing to the illness of its director, Conall Morrison.

Though Supple and Morrison have both done good work elsewhere and in other transfer productions at the National, people are wondering why so few of the other exciting talents that Nunn's predecessor, Richard Eyre, brought to the theatre have been asked – or, in any case, accepted - the chance to work there since. Eyre's National saw the likes of Stephen Daldry, Deborah Warner, Declan Donnellan, Matthew Warchus, Sam Mendes and even Nunn himself invited to the South Bank. Nunn hasn't been inclined to, or able to, attract the same big names. The biggest name to date remains his own. Admittedly, Nunn s own recent productions - including such stunning work as The Merchant of Venice, Summerfolk, Albert Speer and Oklahoma! - have been among the best things in town. But the National, with three theatres to fill, has to be about more than one man's taste and talent.

As a result, while no one disputes that Trevor Nunn is himself a great director, many wonder if he is a good producer. He also hasn't produced an heir-apparent. While there were a number of Eyre-apparent's in the running to have taken over from Sir Richard if Nunn hadn't done so, who is now positioned to take over from Nunn? It's a critical question that needs to be answered.