The cheapest way to fly from London to Brussels, as far as I know, is on Richard Branson's Virgin Express; a return ticket costs pounds 79. The last time I mentioned this, though, someone from the Belgian airline Sabena phoned to say that his fare was only pounds 74. So it is - until you add pounds 15 in British and Belgian taxes.

You wouldn't expect to go into an off-licence and see the price of a bottle of Scotch quoted free of tax. . Air travel is taxed in the much the same way as alcohol, with a variety of duties applied to fares.

On the basis that you, reasonably enough, simply want to know what flight to Brussels (or a can of lager) will cost you, all the fares quoted in The Independent's travel editorial include pre-payable taxes. I suspect you are not especially concerned with what proportion goes to the airline, travel agent or government - you just want a cheap flight to Brussels, or wherever.

Yet airlines and travel agents continue to behave as though taxes were irrelevant. So do some public relations consultants acting on their behalf: I have a stack of press releases promoting cheap fares that do not mention the existence of taxes. These include one "special offer" in which you discover when you inquire further that the tax is actually more than the basic fare.

Travellers should be concerned about the way in which governments see us as easy targets for tax, but pretending Air Passenger Duty doesn't exist won't make it go away. Indeed, the Chancellor's tax on air travel is due to double in November. When it does, even the Virgin Express fare to Brussels will look a lot less attractive than the pounds 59 return on Eurostar trains from London Waterloo. Luckily for Mr Branson, he owns a slice of Eurostar, too.

Few have done more to demonstrate the power of branding and image than Richard Branson. He uses it at every turn to promote his products.

At the start of the Virgin Holidays brochure, for example, Mr Branson tempts potential customers with the promise of Virgin Atlantic's unique service - seat-back videos, free drinks, planes with four engines, that sort of thing. Whether you are more concerned with the extra safety margin of four-engined aircraft or the extra slug of gin in your tonic, you have to agree that Virgin Atlantic is a distinctive airline.

Caroline Metcalfe of Essex was persuaded, and duly booked a skiing holiday to the American resort of Stowe. She was due to fly out on Virgin Atlantic next weekend, enjoying the in-flight service all the way to Boston. But two weeks ago Virgin Holidays wrote to say that the Boeing 747 used for this route is to be temporarily withdrawn from service this week.

"The alternative service," says the letter, "will be operated by a Martinair Boeing 767 ... However, we are certain that Virgin Atlantic will still provide their usual high standard."

Now, I have never flown on the Dutch charter airline that is stepping in tor replace the Virgin jumbo. But I do know that Boeing 767s are much smaller and have just half the number of engines that Virgin Atlantic's planes enjoy, and that they travel rather more slowly than 747s. Furthermore, the in-flight entertainment on a Martinair 767 does not match that offered by Virgin Atlantic: probably the only person lucky enough to have a seat- back video is the flight engineer. That does not strike me, or Ms Metcalfe, as equal quality. So she called Virgin Holidays.

The company offered a change of dates, but Ms Metcalfe had to make the trip during school half-term. Eventually, she was offered a refund, which she accepted. And then she devised a solution of consummate elegance.

Ms Metcalfe phoned the ski resort hotel, which agreed to honour the booking. She then called British Airways, and reserved seats on a BA 747 to Boston, and booked a rental car. She calculated the costs involved, and found she would also save pounds 100, compared with the price in the Virgin Holidays brochure. Next time, says Ms Metcalfe, "I'll organise everything for myself, from scratch".