In the sweep conducted in October, GVH found the use of deceptive "dark patterns" on airlines' websites used to get consumers to take decisions they may not have otherwise taken.

Most platforms put "psychological pressure" on consumers by using messages suggesting scarcity, such as "Just two more tickets available at this price", the office added.

If airlines don't act on the suggestions, the authority said it could launch a probe for compliance with fair market practices rules.