New COVID-19 laws coming into force next week mean anyone leaving the United Kingdom without a "reasonable excuse" could face a fine of 5,000 pounds ($6,900).
Members of Parliament will vote on the proposed laws, part of legislation known as the Coronavirus Act, on Thursday. It is understood that a "reasonable excuse" would include travel for work, education or medical treatment. If approved, the law would come into effect on Monday.
The proposed legislation also states that protests will be considered a "permitted exception "to the ban on mass gatherings, provided they are "organized by a business, a charitable, benevolent or philanthropic institution, a public body or a political body".
A third wave of novel coronavirus cases across Europe and a slow vaccination rollout in many countries has damaged hopes many Britons had for vacations this summer, and ministers have urged the public to delay booking holiday trips in case they are not possible.
The new regulations will not expire until June 30, though Health Secretary Matt Hancock suggested foreign holidays could be allowed before that date, but that it was "too early to say" for sure.
Hancock told the BBC Today program on Tuesday that the ban on leaving the UK "without good reason" would not change the road map out of lockdown plans for international travel announced last month by Prime Minister Boris Johnson.
The road map had indicated that the earliest date people would be allowed to travel abroad for non-essential purposes, such as holidays, would be May 17.
Travel companies, airlines and holidaymakers all rejoiced at the prospect of a full summer holiday season, though Johnson had cautioned that this date would be subject to a number of conditions.
How international travel might work depends on the recommendations from a report due to be delivered by the cross-government global travel task force advisory body. Hancock said the task force would report its findings by the middle of April.
The task force is understood to be considering a tiered "traffic light" system for international travel. People from countries on a so-called red list are currently not allowed to travel to the UK, and British nationals or residents returning from those countries must quarantine on arrival.
Speaking to Sky News, Hancock said: "It is now too early to know where the global travel task force will come out and know what the decision will be for May 17.
"The reason for that is that we are seeing this third wave rising in some parts of Europe and we're also seeing new variants.
"It is very important that we protect the progress that we have been able to make here in the UK."
Helen Whatley, the social care minister, said on Monday that rising novel coronavirus infection rates in Europe added to uncertainty.
"My advice would be to anybody right now is just to hold off on booking international travel," she told the BBC.