Portugal was the premier destination among the 12 countries named on the UK government’s first travel green list last Friday (7 May); however, despite the confident tone struck in recent weeks by Portugal’s tourism secretary Rita Marques and the country’s tourism authority, airlines and operators have been left in limbo by the government’s decision – just days before international travel is due to restart.

The country is also awaiting clearance from the European Commission to open up to third country nationals, who are currently banned from travelling to the EU for non-essential purposes. The Times reports Portugal was expecting the commission to lift the ruling on Sunday (16 May) but that this may now slip to next week.

From Monday, people in England, Wales and Scotland, which have all adopted the same traffic light system laid out by the UK government, will be able to travel to Portugal with no return quarantine requirement.

But Portugal’s cabinet office minister Mariana Vieira da Silva on Thursday (13 May) signalled no decision had yet been made on whether Portugal would lift its restrictions on arrivals from the UK.

She said work was ongoing and that a decision would be announced as soon as possible, but stressed no decision was taken at a meeting of Portugal’s cabinet on Thursday. The country’s "state of calamity", which is extended in 15-day increments, has been rolled over to 30 May.

A delay would be a major headache for the UK’s travel sector, which has over the past fortnight banked on a resumption of travel to Portugal; Tui, easyJet and Ryanair have all committed to operating to Portugal from Monday with dozens of flights to Faro, Lisbon, Porto and Madeira scheduled.

EasyJet, on Thursday, announced it was adding another 25,000 Portugal seats, on top of the extra 80,000 it was already offering.

Responding to passengers on Twitter, easyJet said: "We have been assured a decision will be taken this Thursday to remove the current ban on passengers from the UK into Portugal with plans to lift it on Sunday ahead of international leisure flights resuming on Monday 17 May."

Tui said in a statement posted to its website it was monitoring the situation closely with regards to flights and holidays due to depart between 17 May and 30 May to mainland Portugal, promising a further update "as soon as we have clarification from the Portuguese government".

It said all holidays to Madeira and Porto Santo would operate as planned and that, at present, all holidays to Portugal (Algarve) departing from 31 May would also continue to operate as planned.

Customers will be contacted directly if their flight or holiday is affected; their options will include a full refund or the chance to change their holiday for free.

The Champions League final, on 29 May, which will see Chelsea take on Manchester City, has provisionally been moved from Istanbul to Porto after Turkey was placed on the UK government’s red list.

It is unclear at this stage what effect Portugal’s decision to extend its state of emergency will have on the final going ahead in the city, and whether British fans will be able to attend.