British holidaymakers hoping to jet off to Portugal as soon as UK travel restrictions lift are facing uncertainty after the nation’s government decided to extend its “state of calamity” until at least May 30.

Prime Minister Boris Johnson announced on Tuesday that as of May 17 the “stay in the UK” restriction will lift, meaning people will be able to travel to green list countries such as Portugal without self-isolating on their return.

But guidance published on the Portuguese government’s website on Thursday stated that ministers had approved a move to continue the current level of lockdown until May 30 at the earliest.

UK holidaymakers are currently prohibited from entering the European Union.

Holiday firms have reported huge demand for trips to Portugal following the publication of the green list.

EasyJet has added 105,000 extra seat to its flights serving green tier destinations, while Tui plans to use aircraft which normally operate long-haul routes to accommodate the surge of people booked to fly to Portugal.

A spokeswoman for Tui said: “We’re monitoring the situation closely and will provide a further update as soon as we have clarification from the Portuguese government.

“We would like to reassure customers that we will contact them directly if their flight or holiday is impacted to discuss their options, this includes offering a full refund or the chance to change the holiday for free.”

Simon Cooper, chief executive of online travel agent On the Beach said the situation “illustrates precisely why now is not the time to encourage new holiday bookings for this summer”.

The company stopped selling summer holidays on Wednesday due to a lack of “certainty or clarity” in relation to travel rules.

Meanwhile, the Portuguese archipelago of Madeira is open for tourism.

Thousands of British football fans are hoping to travel to Porto in mainland Portugal for the all-English Champions League final between Manchester City and Chelsea on May 29.

Uefa previously confirmed that 6,000 tickets would be made available to each of the finalists, with the final capacity limit at the Estadio do Dragao still to be fixed.

According to the BBC, Portuguese cabinet office minister Mariana Vieira da Silva said in a briefing on Thursday she had “no information to give yet” when asked if restrictions on travel from the UK would soon be lifted.

Cristovao Norte, Portuguese MP for the Algarve, said a decision should be taken “immediately”.

He told BBC Breakfast on Friday: “We are today going to make an urgent inquiry asking the (Portuguese) government whether or not the English travel can come to Portugal next Monday because we are three days ahead from 17th and no one is sure what is going to happen.

“Our vaccination process is going steadily and it is important a decision is taken immediately.

“The message is clear: there are no reasons, nor political or scientific reasons to maintain restrictions for travel from the UK to Portugal.”

Ms Vieira da Silva said under current plans for the Champions League final, a series of restrictions to British fans would apply.

As well as the limit on ticket sales, fans will have to fly in on charter planes, arriving and leaving “on the same day”, the BBC said.

Ms Vieira da Silva described the plans as “a bubble situation”, with fans passing through a separate zone at the airport and needing a negative coronavirus test before travelling.

Guidance from the Department of Transport warns that many green list countries still have restrictions on UK travellers.

It advises passengers to check all entry and testing requirements and Foreign, Commonwealth and Development Office (FCDO) travel advice for Portugal before booking travel.

It is understood the UK Government has been in discussion with Portuguese representatives this week to discuss plans to unlock travel between the two countries.

The Government is also in talks with the European Commission on how to safely reopen travel routes on the continent, the PA news agency understands.

During the “state of calamity”, entry to Portugal is only allowed if you are a returning resident, according to information on the FCDO website.

Entry to non-residents is limited to essential purposes from the UK and other non-EU countries, and EU or European Economic Area countries where the case rate is above 150 cases per 100,000 residents.

“Essential purposes” are defined as travelling to live with immediate family members or professional, educational, health or humanitarian reasons.

To enter Portugal, proof of a negative Covid-19 test taken with 72 hours of departure is required.

Those without proof of a negative test can be refused permission to board a flight, or may be forced to quarantine in government-approved accommodation upon arrival.