The competition watchdog has said it will investigate the price of PCR coronavirus tests, as well as their reliability and quality of service.
Travel firms have complained that the price of PCR tests are putting families off booking a holiday, with costs reaching as much as £1,000 for a family of four.
We've looked into how much PCR tests can cost here.
The number of PCR tests you need to take before, during and after your holiday is dependent on the travel light system, as well as what part of the UK you live in.
England, Scotland, Wales and Northern Ireland currently have the same green list, while England has an additional green watch list.
It means every traveller from the UK has to take at least one test before they fly back home - this can be a PCR or antigen test - and then get tested again at least once after getting back.
Do you think PCR tests are too expensive? Let us know in the comments.

The Competitions and Markets Authority (CMA) has confirmed it will launch a probe into PCR providers after being asked to investigate by Sajid Javid.
The Health Secretary called for a review into "excessive" pricing and asked the CMA for advice on how the government could "stamp out" exploitation.
In response, the CMA said it was aware of concerns "about price, the quality of service people are getting from test providers, and what happens when things go wrong".
George Lusty, CMA senior director for consumer protection, added: “It is essential that people paying for PCR tests are treated fairly, get what they pay for and that their rights are respected when things go wrong.
“We will not hesitate to take enforcement action if we find evidence that PCR providers are breaching consumer law."
Consumer watchdog Which? has said the clock is ticking to protect those heading abroad this summer from exploitative prices.
A spokesperson said: “Which? has been warning the government for several months that the cost of private testing for travel in this country is comparatively and prohibitively high.
“Currently, an unvaccinated traveller on a return trip to Spain requires four tests totalling an estimated £219 per person, and even if you are vaccinated it’s still close to a hundred pounds.
“Much of that cost is because of the high price of tests in the UK.”
Latest PCR prices
Sadly, you can’t use free NHS coronavirus tests for holiday purposes, which means you’ll need to pay.
There are several ways to purchase a fit-to-fly PCR test, so make sure you shop around to find the best prices.
Prices do change by the day and will vary depending on your vaccination status and where you're entering the UK from.
PCR home tests bought from the high street can cost around £65, or £85 for in-store testing. If you go to a private clinics, the prices can then rise to around £200.
Or at the airports, Gatwick has both drive-through and walk-in test centres and they're currently charging £60 per passenger.
Some holiday firms– such as TUI – are offering test kits for as little as £20 per person making it more affordable, if you’re travelling with them.
It is worth checking your holiday provider as their prices can be more affordable for families.
Which? says the average price for a round trip to Spain is £91 which includes a pre and post travel test. This rises to £219 for four tests if you’re unvaccinated.
A return to Greece also costs £91 return, or £173 for four tests if you’re unvaccinated.
You can only visit France if you have been fully vaccinated – and the average price is £134 for all three tests on the amber list country.
Italy is £130 for all three tests or £173 for four tests if you’re unvaccinated.