From 4am on Tuesday 7 December, travellers arriving in the UK must have evidence of a negative result from a Covid-19 test taken in the two days before their departure.
For example, if their journey begins on a Friday, they could take the test any time on the Wednesday, Thursday or Friday.
But just when will the next review into travel restrictions be held, and what could travellers expect to be changed?
Here is everything you need to know about it.
When can we expect the next travel list review?
Throughout the pandemic, when it comes to the issue of announcing new or changed travel restrictions, the Government has by and large operated on a three week system.
That has meant that any changes to the rules have come three weeks after the last batch of changes.
If that system is to stay in place, then travellers can expect the next batch of announcements on 4 January 2022, three weeks after the last, 14 December announcement.
As always, the situation around the Covid-19 pandemic - and in particular the new Omicron variant of concern - is always evolving, and situations can change suddenly and without much warning.
For instance, that last 14 December update came just 10 after the previous revision to the rules, and as we learn more about the new variant, restrictions could change much more often than usual.
Health Secretary Sajid Javid said “we are taking decisive action to protect public health” when the latest rule changes were announced.
Javid told MPs the Government was taking “early action now so we don’t have to take tougher action later on”.
He said: “When this new variant is appearing in more and more countries every day we also need to look beyond the red list and strengthen our measures for a wider range of travellers to make sure they give us the protection we need against this potential threat.”
What could change?
It’s hard to predict just what could change at the next review of travel restrictions, but potential travellers will be crossing their fingers that the spread of Omicron does not require the reintroduction of the ‘red list’.
The World Health Organisation (WHO) has also said travel bans to control Covid-19 are ineffective and will not stop Omicron, as it urged countries to stick to tried and tested methods.
Speaking to reporters, Dr Hans Kluge, WHO’s regional director for Europe, said that bans on flights did not work and were too late “because Omicron is already everywhere”.
Dr Catherine Smallwood, the senior emergency officer at the WHO Regional Office for Europe, said travel bans “are not effective in preventing spread of disease.”
She said bans on flights and other restrictions were “unfair” and had economic consequences “but most of all they’re not effective”.
What happens if there’s a lockdown?
Boris Johnson is said to be considering imposing limits on household mixing over Christmas to tackle the spread of the Omicron variant.
The strictest of the three options is thought to include a possible full, country-wide lockdown, but ministers have reportedly resisted calls from scientific advisers to introduce new Covid-19 measures before Christmas.
Asked about ruling out new coronavirus measures before Christmas, Health Secretary Sajid David said there is still “a lot of uncertainty”, but now is the “time to be more cautious”.
He told The Andrew Marr Show on BBC One: “There are no guarantees in this pandemic, I don’t think.”
If a full lockdown was ordered, it would likely affect the travel restrictions in a significant way.
As it stands, there’s no way to no what is coming down the road until official government updates. We’ll update this article as and when anything changes.
A message from the editor:
Thank you for reading. NationalWorld is a new national news brand, produced by a team of journalists, editors, video producers and designers who live and work across the UK. Find out more about who’s who in the team, and our editorial values. We want to start a community among our readers, so please follow us on Facebook, Twitter and Instagram, and keep the conversation going. You can also sign up to our newsletters and get a curated selection of our best reads to your inbox every day.