The government has refused to confirm whether foreign holidays will be permitted from 17 May – and where Britons will be able to travel without self-isolating on their return.
A traffic light system is going to be introduced to categorise countries based on risk, and Transport Secretary Grant Shapps says the UK will work with the travel industry and private testing providers to reduce the cost of foreign trips.
This could lead to free COVID-19 tests before departure, and less expensive tests when holidaymakers return.
A report by the Global Travel Taskforce suggests that international travel could resume from 17 May "in an accessible and affordable way" – and passengers would no longer need to prove they have a valid reason to leave the UK.
But firmer details of what will be allowed under the new measures – and when – may only emerge in a few weeks.
The Department for Transport said: "It is too early to predict which countries will be on which list over the summer, and the government continues to consider a range of factors to inform the restrictions placed on them.
"We will set out by early May which countries will fall into which category, as well as confirming whether international travel can resume from 17 May."
Relaxation of travel rules could be delayed if the government believes it will risk the success of the vaccine rollout – and will only resume if vaccines are reducing hospital admissions and deaths enough, infections are not at risk of overwhelming the NHS, and there is not a fundamental change in risks from variants of concern.
Under the traffic light system, assessments will be based on a range of factors, including the proportion of a country’s population which has been vaccinated, rates of infection, emerging new variants, and the country’s access to reliable scientific data and genomic sequencing.
Restrictions will be "formally reviewed" on 28 June to take account of "the domestic and international health picture and to see whether current measures could be rolled back", the department added.
Further reviews will take place no later than 31 July and 1 October.
Tim Alderslade, the chief executive of Airlines UK, said the framework "does not represent a reopening of travel as promised by ministers".
He added: "The insistence on expensive and unnecessary PCR testing rather than rapid testing – even for low-risk countries – will pose an unsustainable burden on passengers, making travel unviable and unaffordable for many people."
Karen Dee, the head of the Airport Operators Association, said the announcement "offers only a glimmer of hope to an industry battered by more than a year of near-complete shutdown".
She said: "Transparent criteria for countries in each travel tier and an indicative green list along with a firm commitment to reopening on 17 May would boost consumer confidence and we urge the government to publish these shortly."
EasyJet chief executive Johan Lundgren said the plan was "a blow to all travellers" and risked "making flying only for the wealthy".
He added: "As the rest of British society and the economy opens up, it makes no sense to treat travel, particularly to low-risk countries, differently."
Mark Tanzer, boss of travel trade organisation Abta, said permitting the use of lateral flow tests would "make international travel more accessible and affordable whilst still providing an effective mitigation against reimportation of the virus".
It has also been revealed the Civil Aviation Authority will be given additional enforcement powers to act on airlines that breach consumer rights, after many passengers struggled to obtain refunds when flights were grounded.