Uefa has said it may need to move the final matches of Euro 2020 football tournament away from London over the UK government’s pandemic restrictions for travellers arriving in England from abroad.

European football’s governing body said on Friday that it remains “confident” the semi-finals and final of the competition will be played at Wembley Stadium in July, but that “there was always a contingency plan.”

Uefa is concerned about the need for fans and VIP delegates arriving from abroad having to comply with strict quarantine measures, and has sought exemptions for the thousands seeking to attend the games.

The demand has left UK prime minister Boris Johnson needing to strike a difficult balance. Though his government wants to keep the flagship matches of the tournament, they are also under pressure from political opponents, who have accused ministers of being too slow to enforce border restrictions in recent months.

The spread of the Delta variant, which first originated in India, led Johnson to extend domestic curbs, including on mass gatherings, beyond the planned date to lift all coronavirus-related restrictions on June 21.

That decision ended hopes of the final Euros matches being played in front of a full capacity crowd of 90,000 people at Wembley. The government has announced it will allow 40,000 spectators to attend the three games, up from around 22,500 for England fixtures talking place at the stadium this month.

People close to the negotiations said concessions were likely on either side. The UK is moving towards shorter quarantine periods for those attending the Euros, while Uefa may accept the need for further limits on the numbers of overseas arrivals.

Uefa said: “At the moment, we are in discussions with the local authorities to try to allow fans of the participating teams to attend the matches, using a strict testing and bubble concept that would mean their stay in the UK would be less than 24 hours and their movements would be restricted to approved transport and venues only.

“We understand the pressures that the government face and hope to be able to reach a satisfactory conclusion of our discussions on the matter. There is always a contingency plan but we are confident that the final week will be held in London.”

Downing Street said: “No decisions have been taken, but we continue to look forward to putting on the semi-final and final at Wembley and we’re working closely with Uefa.”

If existing quarantine measures, which require travellers from amber and red list countries to self-isolate on arrival for several days, are applied then Uefa is still likely to move the matches away from Wembley.

The football governing body moved the Champions League final in May away from Istanbul after the UK government moved Turkey on to its red list and advised supporters of the two participating English clubs, Chelsea and Manchester City, not to travel to the game.

Talks were then held to move the game to London, but the UK government refused to relent on quarantine restrictions for VIP delegates based across Europe, leading Uefa to stage the match instead in Porto, Portugal.

A person close to the discussions said Budapest in Hungary, which has been staging Euros matches to full crowds with few restrictions, is the likeliest destination should the semi-finals and final game be moved.