Dublin is on the brink of relinquishing its status as one of the 12 Euro 2020 host cities after failing to offer a guarantee on minimum spectator levels. European football’s governing body, Uefa, had set a deadline of Wednesday for countries to confirm stadiums would be at at least 25% capacity for the tournament this summer. But the Football Association of Ireland said it had been unable to do so “owing to the Covid-19 pandemic”. Its four matches – three group games and a last-16 match possibly involving England – are highly likely to be switched, with at least one earmarked for Wembley. A decision is expected on Friday once Uefa’s steering group, which involves the 12 national organisations involved in Euro 2020, has met. England are planning to have 21,000 fans inside Wembley for their opening Euro 2020 match against Croatia on 13 June, but that number is expected to swell significantly as the tournament progresses. Last week the culture secretary, Oliver Dowden, said he hoped there would be “big crowds” for the semi-finals and final at Wembley. The Scottish government has given approval for 12,000 supporters – 25% of the stadium’s capacity – to attend Euro 2020 matches at Hampden Park. Other cities – including Copenhagen, Bilbao and Amsterdam – have also indicated they will fill their stadiums to 25% while St Petersburg has said its stadium will be at 50%. Dublin is the only host city not to have offered a guarantee on fans. Tottenham and Manchester City will be given 2,000 tickets each for the Carabao Cup final at Wembley on 25 April but City fans face having to use special Covid-secure transport if they want to attend. Supporters from both teams will also have to prove they are free from Covid – probably via a certificate showing they have had a vaccination, negative test, or have immunity. However Trevor Birch, the chief executive of the Football League, admitted several issues were up in the air – including whether supporters would be allowed to sing or be required to wear masks. “Covid-safe transport is being discussed,” said Birch. “Unfortunately I can’t go into the details because it is still in train. It’s obviously quite a complicated process. There are a lot of stakeholders involved in the discussions.” In total 8,000 fans will be allowed to watch, with other tickets given to local residents in the borough of Brent and NHS staff. “All will be revealed in the next week or so, in terms of the dos and don’ts,” Birch said. With Football League clubs having lost about £250m since the start of the pandemic, Birch stressed it was vital that grounds were back at full capacity for the start of the 2021-22 season in August. However he admitted clubs may have to restrict those fans who had not had the vaccine, were extremely vulnerable or pregnant. “Hopefully the Covid certification will deal with much of it. But it is incredibly difficult to be certain about what procedures will apply.” Meanwhile a capacity crowd is expected to be able to attend the final of the 2021 World Snooker Championship at the Crucible in early May. The event in Sheffield, which begins next week, will be the first sporting competition included in a pilot programme to enable the return of mass gatherings as lockdown restrictions ease in England. Organisers confirmed the Crucible would be a third full for the first round, at 50% for the second round, and at 75% for the quarter-finals and semi-finals – before a full-capacity crowd of 980 people would be allowed for the final. But under the pilot scheme no one under 18, adults deemed clinically extremely vulnerable, or pregnant women will be allowed to attend. Spectators will also have to take a Covid-19 test before they arrive, and must show confirmation of a negative result to enter the venue, and then take another test five days afterwards at home.