Hotel booking sites must review the way they rank and display rooms, says the Competition and Marketing Authority (CMA).

The watchdog said some sites may be making misleading claims about discounts, as reported by the BBC.

The CMA is also looking into whether sites are giving a false impression of room availability and rushing customers into booking decisions.

The CMA has not named the companies it has been investigating, but leading sites include Expedia and Booking.com.

The CMA launched its investigation in October and says it has sent warning letters to a number of sites, demanding they review their practices to make sure they are fair and comply with consumer protection law.

Concerns include:

* How search result rankings are influenced by factors irrelevant to consumers, such as how much commission a hotel pays the site

* Whether a false impression is created by claims about how many people are looking at the same room, how many rooms are left, and how long a price is available

* Clarity over discounts, including whether a weekday rate is being compared to a previous weekend rate

* Whether holidaymakers are hit with unexpected extra charges later in the booking process

About 70 per cent of people who shop around for accommodation use hotel booking sites, according to the CMA.

The watchdog has ordered the sites to review their practices and to respond within the next few months.

At the end of the review, the sites can either give a legally-binding commitment to change their practices or argue that they are not breaking the law.

If the CMA disagrees with their arguments, it can take the companies to court, where they could face unlimited fines.

What do you think? Email mark@moosemarketingandpr.co.uk