A new framework for international travel that proposed the introduction of a "traffic light" system was unveiled last week.
The system will sort countries into green, amber and red categories depending on infection rates and the prevalence of Covid-19.
Green areas will have fewer restrictions and red areas will have the most.
The main differences centre on the rules on quarantine. Those coming back to the UK from green countries won't need to quarantine, unless they test positive upon arrival. People travelling from amber and red listed countries will be made to do so.
The approach has been recommended by the Department of Transport and it's hoped it will help international holidays to resume in an "accessible and affordable way".
The planned approach by the UK Government prompted updates over the last week by Jet2 and TUI - with some holidays set to be cancelled in the wake of the proposed 'traffic light' system, North Wales Live reports.
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Jet2
Following the publication of the framework, Jet2 announced that it would be cancelling additional holidays - confirming that it would extend the suspension of flights and holidays up to and including 23 June, 2021.
The travel provider said this was with a "heavy heart" but that it was as a result of "continued uncertainty."
It means bookings between May 17, the earliest travel can resume, and June 23 won't go ahead as planned.
Customers affected by the change will receive a full refund, as their booking will be automatically cancelled, and a Jet2 representative will be in touch "to help them book their summer getaway for later in the year."
You can find out more about Jet2's upcoming schedule and any changes by visiting its website.
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TUI
The prospect of the 'traffic light' system for summer travel had been expected by some within the industry, so TUI issued a response to the approach earlier last week - even before the framework was unveiled.
Although its response was issued prior to the framework's publication, the travel provider said the 'TUI Holiday Promise' for green and amber destinations would "remain the same for continued peace of mind."
It explained: "If prior to your departure date you know that you will need to quarantine on your return to the UK, you will have the option to change your holiday for free to another time."
Customers have been assured that they will also be able to change their holiday for free if they're unable to travel due to new testing or vaccination requirements.
Even before the official framework was unveiled, TUI asserted that it wouldn't operate holidays to destinations "that will require you to quarantine on arrival or those on the Red list."
The travel provider said that in these circumstances, holidays will be cancelled and affected customers will be entitled to amend it for another date, for free, or they can request a full refund instead.
And TUI has extended its free changes policy with those due to travel between May 17 and the end of July able to change their booking to a later date fee-free online or by calling 0203 4512688.
You can find out more about TUI's schedule for the summer and any changes by visiting its website.
