A Christmas tree twinkles beside the bay window of the spacious London flat in which Alan Ayckbourn's new comedy Sugar Daddies is set.

The action begins with Santa Claus himself entering through the front door. Are we in for more festive fun (and fiascos) in the style the great playwright offered in, say, Seasons Greetings and Time and Time Again?

Not really -- for Christmas is over by the time the second of the eight scenes begins. What we are shown from then on is how it becomes Christmas every day of the week for the lucky young lady who has done Santa a good turn.

Alison Pergeter as Sasha with Terence Booth as Ashley She is Sasha, a naive youngster, not long in town and still with the strong East Anglian burr of her native King's Lynn (which the Oxford-born actor Alison Pargeter manages well in a generally excellent performance).

She shares the flat with her neurotic and rather snooty half sister, Chlo (Anna Brecon), a TV researcher. Chlo is terrified of crime and is livid when she arrives home to find a total stranger has been let in.

But can she have any reason to fear Val (Rex Garner), the elderly cove in the red Father Christmas suit? He has narrowly escaped injury moments before in a car accident in the street outside as he walked home from delivering presents to a local hospital. Sasha has brought him to the flat to recover from the shock. It is a lucky meeting for her.

As they chat, this grandfather many times over -- he claims to be a retired police chief -- steadily starts to fall for her, purely platonically it would seem. As the days and weeks pass we follow this "gradually growing friendship", as Sasha styles it. He showers her with gifts, takes her to the opera, to restaurants, to nightclubs -- in short, gives her the time of her life.

Of course, it is all too good to be true. Far from being a bastion of the law, Val has been a lifetime breaker of it -- a godfather of crime involved in prostitution and all manner of other rackets. We learn this from Ashley (Terence Booth), a genuine cop who moves into the flat below and becomes another of Sasha's pals.

All the simmering trouble bursts into the open when one of Val's 'girls', the tarty Charmaine (Eliza Hunt), tells a few home truths at a disastrous dinner party hosted by Sasha -- classic Ayckbourn mealtime scene.

This is an entertaining, thought-provoking play. Its main theme is that 'we are who we are' and that it is almost impossible to re-invent ourselves to suit changed circumstances. Sasha will ever be the bumpkin, Val the villain.

The trouble is that it all rather goes on a bit -- two hours 40 minutes with interval.

Another director might have taken the red pencil to parts of the script. But this director is Sir Alan himself.