The Consumers' Association (CA) has backed calls for the government to regulate travel insurance.
The announcement comes as new CA research uncovered evidence of mis-selling in the industry.
The findings highlighted that only three branches of the major national chains it visited asked about pre-existing medical conditions.
CA spokeswoman Louise Hanson said: "Today's findings are enormously concerning. Until the Treasury commits to regulating insurance sold by travel agents, thousands of consumers run the risk of going on holiday with insurance that may not cover them if something goes wrong.
"It is unacceptable that protection for consumers buying travel insurance should be dependent on where they decide to make their purchase. The Treasury needs to take this opportunity to stamp out this half-baked approach to consumer protection and implement full regulation incorporating travel agents."