The government has confirmed its pre-departure Covid testing regime for UK arrivals will come into effect on Friday (15 January).
All those due to arrive in the UK after 4am on Friday by air, sea or rail will have to present evidence of a negative test result.
Tests must be taken up to a maximum of 72 hours prior to departure.
The new measures come in addition to quarantine rather than replacing it, with all arrivals – including those arriving from travel corridor destinations – required to test negative before departure.
Following speculation over the new year, prime minister Boris Johnson last week revealed pre-departure testing was under consideration, with several cabinet ministers later hinting at an imminent intervention.
Transport secretary Grant Shapps then made a statement on the matter on Friday (8 January), confirming the new measures would be implemented in the coming days but gave no definite timescale or guidance on the standard of test that would be accepted.
Setting out the plans in greater detail late on Monday (11 January), aviation and maritime minister Robert Courts reiterated the move provided "a further layer of protection to safeguard public health".
Courts said tests much be of a diagnostic standard such as the PCR test required by a number of other countries, although he said LAMP and lateral flow tests "could in some cases" be accepted "within set limits".
He said "clear guidance and advice to passengers regarding testing standards and capacity" would be provided by the government, albeit while again offering no timescale.
Those travelling to the UK will have to show evidence of their negative test certification at check-in; Courts said information passengers will be required to show at check-in will be made available to passengers and transport operators via gov.uk, again with no timescale.
It will left to transport operators to check for evidence of a pre-departure negative Covid test result, with UK Border Force officials carrying out spot-checks at UK ports of entry.
Fines for non-compliance start from £500pp, and there could also be fines for transport operators carrying non-compliant passengers.
People travelling to England from the Common Travel Area, comprising the UK, Ireland, Isle of Man, Jersey and Guernsey, will be exempt, as will children under the age of 11.
Arrivals from three overseas territories, St Helena, Ascension Island and the Falkland Islands, will be permanently exempt from meeting the pre-departure testing requirement owing to a lack of testing infrastructure.
The same will apply temporarily to arrivals from Antigua & Barbuda, Saint Lucia and Barbados for the same reason, although this exemption will only run until 4am on Thursday 21 January.
Courts said the new pre-departure testing rules would "likely" remain in place "until the end of the current lockdown", although he added a review could yet take place before the end of that period.
He added the government has "worked closely" with the international travel sector during the course of the pandemic, and stressed ministers would continue to implement the recommendations of the Global Travel Taskforce – a committee on which no travel sector stakeholders were invited to serve.