Afternoon tea with the Women's Institute is exactly as you would expect it. A beautifully laid-up mahogany tea trolley groaning under the weight of three trays of sandwiches either with butter or without and an assortment of different fruit cakes, writes Zahra Akkerhuys.

Since its establishment in 1915 the WI has acted as an important pillar of society. It is a matriarchal body that underlines the belief that the hand that rocks the cradle rules the world.

Jam-making and chair upholstery may be traditional skills the WI does not want to see die out, but they certainly are not only what the organisation is all about.

The WI has shaken off its twin-set and pearls image and become a major force to be reckoned with in the political arena, even though it supports no particular party. Ask Tony Blair about its clout and importance. When the Prime Minister turned up for his first official engagement at the organisation's Wembley conference in June after the birth of his son Leo, he no doubt thought he would be in for an easy ride.

His King of Spin Alastair Campbell was probably thinking he could put up his feet and take a rest, but then the unthinkable happened.

When Blair spoke, aiming to reposition Labour as a party of traditional values in a changing world, he received first a slow handclap and then undisguised jeering from sections of the hall.

The women were only silenced by their chairman Helen Carey who asked them to remember their manners and have the courtesy to allow the Prime Minister to speak.

Director of Education and Training for the National Federation of Women's Institutes (NFWI), Jennifer Adshead, who was sitting next to the embarrassed Prime Minister at the time, says: "The WI is not a force to be under-estimated.

"It has a quarter of a million members across the country and it has certainly become a powerful lobbying force. "We formulate resolutions on topical issues and have several on-going campaigns tackling important subjects such as GM food and buying British."

Oxfordshire is WI heartland.

Members from across the country come to the WI's own residential college, called Denman College, at Marcham, near Abingdon, to finely-tune their WI skills. But the curriculum does not just focus on how to achieve a smooth-running household.

A total of 500 weekend courses are run at the college each year covering an imaginative list of topics ranging from massage and aromatherapy to computing as well as incorporating domestic skills such as home baking and dress-making.

Last weekend's courses included Morse In Oxford, soft furnishings, British Garden History and drawing and painting. The college, which opened in 1948, is based in an elegant Georgian mansion set in 100 acres of splendid grounds. It was named after the NFWI's first chairman Lady Denman.

Jennifer says: "The Women's Institute is one of the only organisations that continues to teach home economics and food skills.

"In many respects they are a dying art. Educational trends mean that children simply aren't learning about nutrition and how to eat a balanced diet."

Research by the Milk Marketing Board has recently showed that youngsters don't know that milk comes from cows, because they believe it comes from a carton in the shop.

Jill Brand, home economics advisor to the NFWI, says the organisation wants to see a change in emphasis in the way youngsters are taught so that they are prepared better for life when they leave school.

The fast pace of modern life means that many women simply do not have the time to spend in the kitchen chained to the stove but the WI aims to teach them how to adapt traditional skills to the modern world. Jill, who also writes recipe books, says: "Children do not understand where their food is coming from nowadays. My role is to get people into learning basic skills.

"When Delia Smith first started doing her 'back to basics' she took a lot of criticism, but I know some people who say they have Delia to thank for the fact they can poach an egg. Many can't cook a Sunday roast.

"We also train cookery judges so that they are capable of judging competitors entries to agricultural or rural shows. When you are judging jams you are looking for colour, consistency and whether the balance of flavour is right.

"With a Victoria Sandwich you want to make sure that it slices in a particular way. It's a question of training the palette but you have to train it to look for the right things."

Only a member of the WI could call a Victoria Sponge a Victoria Sandwich. Jill continues: "I know some people mock what we do but that is up to them. At the end of the day there's no substitute for home-baked food."

And to be honest, there's no arguing with that. Liz Eaton is one of 6,000 women who attended a course at Denman College last year. The 53-year-old woman, from Warborough, took a course in healthy cooking because she wanted to learn about preparing low-cholesterol cuisine.

Liz, chairman of the Women's Institute Oxfordshire Federation, went along with around 70 other members from the county. They learnt to cook using low-fat products such as quark and fromage frais.

She says: "I decided to take the course because my husband has quite a high cholesterol rate. I wanted to get round using cream in everything without just substituting it with tomato.

"We were talked through how to use different products and we learnt to do all sorts of things."

Although Liz lives just a few miles from the college she decided to stay in one of many beautifully-decorated guest rooms.

It would be easy to think that staying at Denman College would be similar to staying at a girls' boarding school but the accommodation could not be more different to draughty dormitories and communal showers.

Each room is decorated and furnished by representatives of different WI federations from all over the country. The Northumberland room's walls have calming scenes of the county's rolling countryside, the Surrey room has been turned into a 19th century-style lady's boudoir complete with cerise curtains and frim frams.

And the guests enjoy hearty meals all prepared in Denman's kitchens to Denman's high standards. The college has several of its own special recipes including Denman Tea Bread.

Liz says: "It's not at all a 'jolly hockeysticks' sort of place. You don't share a dormitory so you have your own space if you need it.

"Denman provides a very supportive environment within which to learn. There's an amazing range of courses that you can do there.

"You can go there without knowing a soul and you will soon make friends. We are fortunate that we are in Oxfordshire and that Denman is on our doorstep."

Liz has recently become a volunteer at Denman and often spends time there when not on a course welcoming guests and helping ensure the smooth-running of courses. You don't have to be a member of your local branch of the WI to go along to Denman College. Many people who do not have the time or inclination to join a branch can become an associate member of the organisation to sign up to attend a course.