Astute travellers are probably aware that they are unlikely to get entirely unbiased advice from Britain's major travel agency chains.

Invariably, the first package they recommend will be from the brochure of a sister tour operator. Only if that holiday does not meet the customer's needs will they suggest one with a firm owned by a rival group. The practice is called directional selling and it has long drawn the wrath of consumer campaigners and smaller travel firms.

As a result of the attendant publicity, assiduous newspaper readers may know that Lunn Poly is part of the Thomson group, that Going Places and Airtours are under the same ownership, that JMC belongs to Thomas Cook and that First Choice and Travelchoice are similarly linked.

But mergers and acquisitions have stretched the web of travel industry connections much wider than that. Are customers sufficiently aware that many small and medium-sized specialist operators have been snapped up by the giants?

What is the difference, for example, between Headwater and Inntravel? They run broadly similar operations. Among other kinds of holidays, both organise walking trips on which your bags are ferried from hotel to hotel. But Headwater is now owned by Thomson while Inntravel remains independent.

Take two small ski operators. Did you know that Flexiski is now part of the First Choice group while rival Meriski's only linked firm is another small, upmarket chalet operator The Ski Company?

From next month, the Government hopes, such distinctions will become much clearer. On October 9, an order under the 1973 Fair Trading Act will come into force obliging the large "vertically integrated" groups - companies that own travel agency chains and tour operations - to list linked companies on notices outside and inside their shops, on brochure covers, stationery and in advertisements.

For some critics it is all too little and too late. As the Association of Independent Tour Operators (AITO) points out, the Government has dragged its feet for two and a half years since the Monopolies and Mergers Commission reported on the issue but has still shied away from one of that report's recommendations - that agents should be required to change the wording on their shop fronts.

Customers may also remain confused about the way the new rules apply to different groups. When he made the order, competition and consumer affairs minister Kim Howells said: "Notices on the outside of shops are particularly important. Consumers should have information about ownership links before they decide which travel agents to visit."

But Thomas Cook says it will not have to display shop window lists of the tour operators it owns because, once customers are inside, all those firms' brochures are over branded with its own name. Commercial director Mike Beaumont says: "We feel slightly aggrieved that the issue has been brought to the fore when we were transparent already."

Provided the customer gets a satisfactory holiday, does it matter who owns what? Yes, says Patricia Yates, editor of the Consumers' Association magazine Holiday Which? Writing in its latest edition she says: "We know that many of our members prefer to travel with smaller specialists because they do not want to feel part of the crowd and they value the more personal service. We think it is disingenuous to claim that you are small and perfectly formed while hiding the fact that you are owned by one of the giant tour-operating groups.

"The number and variety of brands that the big operators own not only allows them to offer unwary customers holidays exclusively from the group, but also to squeeze out their rivals, both large and small. So genuine independents find it increasingly hard to compete. The final joke is that travel agents seem to be limbering up to charge service fees. Do they really believe that consumers will meekly pay for biased, uninformed advice? We don't think so."