While there is no doubt about I Loved Lucy author Lee Tannen's adoration for beloved TV icon Lucille Ball, good intentions and an encyclopaedic knowledge of one's subject do not automatically make decent, or even particularly interesting, theatre.

Tannen's ham-fisted script is lamentably of the "why don't you tell me about the time when..." variety, whereby the less famous character (in this case Tannen himself) asks the more famous character (Ball) a question which then prompts a lengthy reverie and/or anecdote. It's a clumsy device and isn't helped by the fact that most of Lucy's long speeches amount to little more than extensive lists of star names of the period, punctuated by the occasional bitchy comment; there is nothing here that couldn't be gleaned by reading an old movie magazine or looking at Wikipedia. There is precious little dramatic tension and when it comes -Lucy and Lee have a fall out at the end of the first act - it comes from nowhere and is put to bed almost straight after the interval.

Perhaps it is the fact that Tannen and Ball genuinely were friends that prevents this piece from ever catching fire as drama. It's gossipy, mildly catty, ultimately sentimental and overall pretty dull. Every cliche in the book about fading stardom, fan worship and the ageing process are hurled in with reckless, wearying abandon. Anthony Biggs' pedestrian production lacks pace and variety.

As Ms Ball, the wonderfully game Sandra Dickinson really makes one long to see her with a better script. She is feisty, warm, funny, and with a genuine twinkle in her eye. She even looks reasonably like Ball too, although there were a few moments where she reminded me more of a ginger version of Prunella Scales in Fawlty Towers. Opposite her, Matthew Bunn plays Lee with an oleaginous insincerity and a hopeless American accent. His impersonations of some of the other men in Lucy's life are delivered with varying degrees of success.

It says much for the considerable charm of Dickinson's performance that it isn't eclipsed by the final moments of the production where we are treated to a montage of images of the divine Lucy (the real one) to the accompaniment of a recording of her singing "Hey Look Me Over". With a lesser leading actor, that magical finale could very well have seemed like the production team shooting themselves in the foot.

I Loved Lucy runs at Jermyn Street Theatre until February 27.