Desperate housewives they may be, but not in the ordinary sense.

As a new six-part series on BBC Alba shows, a minister's wife scarcely has time to do domestic chores, so much else is expected of her. Far from languishing bored at home, she eyes the mounting pile of ironing, or dust with the sort of controlled panic more commonly seen in A&E on a Saturday night. As one of the three wives featured in The Minister's Wife commented, with a faintly hysterical laugh: "My life is going 100mph."

I tuned into the first episode last Friday, not because I want to brush up on my Gaelic but because if I had to go onto Mastermind, my specialist subject would probably be the minister's wife. Brought up surrounded by ministers and missionaries, like the precocious naturalist Gerald Durrell, I began my observations at a very young age. No magnifying glass was required.

These women were generally larger than life. In an era when few married women had a career, they were pioneers, juggling domestic responsibilities with a second role that was every bit as demanding as a full-time job.

It was also unpaid. Even today, when a parish chooses a married minister, it's getting two for the price of one. It's a wonder the wife is not officially interviewed before the manse is filled. That said, when a minister preaches before a vacancy committee, his partner will be run ruthlessly through the congregation's invisible x-ray machine for signs of hidden defects. I was told of one woman who accompanied her spouse to a prospective parish wearing a plunging neckline. It could have gone either way, but fortunately her husband was soon in post, as was she.

Arguably, her position is the more demanding, combining as it does the skills of secretary, events manager, wardrobe mistress, speech advisor, political aide, boardroom director, spin doctor and therapist. Woe betide the wife who, like a busy lawyer I know, indicated she would not be helping out with the Sunday School or baking cupcakes for coffee mornings. Her husband's reputation never quite recovered.

Indeed, a wife's willingness to act as a ministerial handmaiden has been so taken for granted that until recent times - and in certain parishes not even now - a minister would more easily be forgiven breaking one of the ten commandments than having a wife who refused to be part of a double-act.

One wonders how unmarried ministers manage. Judging by a friend, thoughtful elders are the answer, quietly attending to chores such as weeding, mowing lawns and DIY. Another acquaintance has spoken of less charitable behaviour, one nosy parishioner riffling though her wheelie bin, another wondering why her bedroom curtains were still drawn at a time of day when respectable people were sitting down to lunch.

Sadly, it has always been like that. Being a minister is an all-consuming commitment that transcends the working week or holidays. Everything the clergyman and his wife do, wear or say is freighted. While some obviously thrive on their joint marital task, for others the psychological pressure it exerts can be terrible.

I will never forget the exhausted Hebridean minister's wife who, when her husband had invited my family to stay for a week, saw us coming up the drive and took to her bed. There was a quarter-pound of mince in the manse to feed eight of us, and the next ferry didn't arrive for another two days. It wasn't even Lent.

One sympathises. The minister's wife shares many of the strains of the job with little of the authority or status. There's worse, too. Letters I have received, and others I have seen, suggest the wives of certain kirk ministers who have broken church laws have been dealt with more harshly than their errant partners. Even today, it seems, in some parishes women are considered second-class citizens.

Yet why is a minister's husband never expected to fulfil the range of duties that fall to his female counterpart? Is this die-hard sexism? Are men's jobs deemed more important than any woman's? I prefer to think it's that women have more to offer, and give more willingly. Without the minister's wife and the Herculean, heroic contribution she has made, the church would long since have crumbled.