Penelope: To the manner born

On 3 April, Penelope Keith will become High Sheriff of Surrey. The most celebrated snob in British sitcom will spend a year as the Queen's official representative in the ultimate Home County.

The title is a bureaucratic hangover from medieval times, but it would have delighted her on-screen characters. How bourgeois Audrey Fforbes-Hamilton in To The Manor Born would have flaunted her royal connection! How Margot Leadbetter from The Good Life would have loved increasing the range of her influence (now she could bully not just the Pony Club, the Music Society and the Conservative Club, but most of Surrey as well). It's almost too good to be true.

Like Beefeaters and pots of tea, the High Sheriff is a quaint British institution - the sort of thing that has Americans gee-whizzing with glee and the rest of us glazing over with indifference. All of us except for Penelope Keith, that is. Backstage at the Apollo Theatre, at the end of her five-month stint in No?l Coward's Star Quality, Keith unleashes her enthusiastic Sheriff spiel before I so much as ask my first question. 'It's absolutely fascinating. It's the oldest secular office in the land, second to the crown. Until Tudor times, Sheriffs were really the most powerful people in the land. They were responsible for the entire county: the taxes, law and order, raising armies. Counties were like little fiefdoms,' she says.

Today, however, a Sheriff's duties amount to little more than signing the odd writ and an endless round of back-patting and hand-shaking at local engagements. It sounds a bit like being a second-string royal. But it's clearly something that appeals to Keith, the first actress to be asked (each Sheriff is chosen by an incumbent a couple of years in advance).

Interviewing her feels a lot like taking tea with Margot. Draped in a sheer neglig?e and caked in stage make-up, Keith is extremely tall, very confident and wonderfully upmarket - a kind of glamorous version of Margaret Thatcher. Everything is 'terribly' this, 'rather' that and 'absolutely' everything else. She even says 'mark you' and 'oh, fart'.

Functions and ceremonies will be a breeze, she explains, thanks to her considerable experience. She recites a list of titles that Margot would die for: Keith is president of the Actors' Benevolent Fund, trustee of a foundation for the disabled and of her local theatre; committee member for the Royal British Legion and Prince Philip's Jubilee Appeal, and governor of the Guildford School of Acting. And now she's Sheriff, with a whole new world of duties to her name.

'The office is really part of the social cement of our culture,' she says. 'I've already had a request to go to the prisons, which I think is a terribly good idea. And the WI has invited me to give medals to meals-on-wheels people but, sadly, it clashes with something else.'

If Keith's track record is anything to go by, Surrey could be in for some fun. Four years ago, the Actors' Benevolent Fund enjoyed a sniff of scandal when three full-time staff and four trustees resigned due to Keith's allegedly heavy-handed and bossy presidential methods. She refused to be intimidated by the in-fighting and sent out deliciously arrogant signals by wearing a 'Head Girl' badge to the charity's AGM. She emerged unscathed, but still doesn't like to discuss what she refers to as her 'rather bad time'.

The 61-year-old actress and her 'darling husband' Roddy have lived in a 17th-century manor near Milford in Surrey for over 20 years. She is clearly excited about becoming more engrained in the county's social cement, but to give her credit, her motives extend way beyond Margot-style social aspirations. Keith is generous and genuinely wants to help. She believes in 'voluntary service' and 'the duty of service' and worries that 'today's dreadful "Me Culture"' is going to leave a huge void in the voluntary sector. 'It's all very well giving money to charity, but if there's no one to actually do the good work, then we'll have anarchy, won't we?'

Richard Briers once said of his co-star: 'She could have been a successful politician, but thank God she didn't do that.' He's right. Who else could fight anarchy in Surrey?