Tour operators and travel agents have been accused of using intimidating language to encourage customers to buy their own travel insurance policies.
Two travel brochures have come under criticism by direct insurers. Handmade Holidays and Ski Weekend, which use intermediary Hamilton Barr, advise customers that, if they use insurance bought elsewhere, its resort reps may be powerless to help, as there is no formal arrangement between the insurance company and the operator.
Handmade Holidays' brochure says: "There are instances where we have had people left uninsured because their policy did not cover certain events.
"Sometimes, the insurance company will not talk to us because our rep is not the insured person."
The brochure recommends the tour operator's own "free" insurance for medical cover, plus a "top-up" cover for extras such as baggage.
But direct insurers are calling for greater regulation of tour operators.
Managing director of specialist travel insurer Snowcard, Russell Dadson, warned there was an "inherent danger" in assuming "free" insurance was a better product than clients may have bought themselves.
Dadson said: "The broker puts together the wording on behalf of the tour operator. This is blatant inducement to purchase the insurance based on the operator's desire to maximise his insurance commissions rather than sell an appropriate policy."
According to the General Insurance Standards Council (GISC), only 20 or 30 of its members are tour operators or travel agents and most of the larger ones have not joined.
A GISC spokeswoman said: "We think they should be members.
"Many try so hard to cross-sell and include travel insurance in their holiday packages, that they often do not explain it very well."
But Hamilton Barr managing director Adrian Foley said the wording in the Handmade Holidays brochure was common.
"Companies use the tool of their trade to sell their own product. That is not anti-competitive," he said.
In August, travel insurers came under fire in a report published by the Financial Services Ombudsman (FSO).
Ombudsman Walter Merricks accused travel insurers of failing to explain the small print in their policies.