Summer holidays are approaching - should you buy your flight on a price comparison website? According to the UK’s Competition Market Authority, which is mid-way through a year-long study of digital comparison tools, more than 90% of price comparison users said they were happy with the results.

But, as the CMA hinted in its update earlier this year, the websites are not as transparent as they could be. It is not always easy for consumers to be sure they are getting the best price, or how and why one deal is cheaper than another. Are we getting a genuine bargain or does a low upfront price come at the expense of worse service in areas like flight punctuality?