Sources close to talks with government say it is “too early to tell” if travel will restart on May 17.

The government has boosted hopes of a substantive travel restart from May 17 by this week announcing Portugal’s removal from the ‘red list’ and last week confirming the Global Travel Taskforce report will be published on April 12.

Transport secretary Grant Shapps told MPs he would “make the report public the same day” it goes to the prime minister, giving the industry extended notice of the recommendations.

However, coordination among the devolved administrations appears no nearer. Scotland’s first minister Nicola Sturgeon announced on Tuesday that international travel “may well not be possible” from May 17 and pre-departure and post-arrival testing may remain “for some time”.

Sturgeon said she would discuss with the aviation sector how and when “travel to some international destinations may be possible”.

First minister of Wales Mark Drakeford went further, declaring the prospect of international travel from mid-May “fills me with horror”, and a “senior government official” told The Sunday Times: “The EU vaccine chaos could hit summer holidays. Even if we’ve all been vaccinated, it will be difficult to go elsewhere.”

An industry source dismissed the report, insisting: “It’s too early to tell. A week is a long time in this crisis. We need to hold our nerve.”

However, a second source told Travel Weekly: “It is really uncertain. Health experts are most worried about the ‘variants of concern’. The UK government strategy is to keep quite high barriers and the vaccination approach [in the EU] is hampering our ability to reassure the government.”

On Scotland, the source said: “There have been differences throughout. We hope there will be alignment, but we just need to manage it.”

The source confirmed there should be five weeks to implement the taskforce recommendations, saying: “They wouldn’t present a report that is not signed off.

“The PM will say on April 12, ‘That is what we’re doing’.”

In a separate boost, Turkey confirmed on Monday it would be open to UK holidaymakers without vaccination certificates, with Jet2 and Jet2holidays reporting bookings to Turkey doubled in the subsequent 24 hours.