Sports fans will be required to show proof of a negative Covid test before attending live events in England, as part of a range of measures announced by the government to halt the spread of Covid. A Covid pass that shows evidence of at least two vaccine doses will also be accepted at live sports events, but reports that the vaccine passport would be the only means of gaining access have proved to be unfounded. Boris Johnson announced his plan B on Wednesday evening after figures showed cases of the Omicron variant doubling every two to three days since it arrived in the country. The measures referring to sports events will take effect from a week’s time which means the weekend’s fixtures, notably in football and rugby union, will be unaffected. There will be some exceptions for smaller events too, but the rule will apply to outdoor seated events with a capacity of more than 10,000 people and outdoor standing events that can hold more than 4,000 people, as well as indoor events with capacities greater than 500. “We will make the NHS Covid pass mandatory for entrance into … spaces where large crowds gather,” Johnson said. “Having taken clinical advice since the arrival of Omicron, a negative lateral flow will also be sufficient.” Mask wearing will not be required at outdoor events, regardless of the crowd size. They will be mandated at indoor events, however, with exceptions made for athletes and for gyms and gym users. Johnson described the new measures as “proportionate and responsible” with the health secretary, Sajid Javid, telling the House of Commons that the number of Omicron cases in England could be as many as 10,000. The changing picture means most sports organisers will be anxious about further regulations in the weeks ahead. Two Premier League teams – Leicester and Tottenham – have revealed Covid outbreaks in their squads, and Spurs are likely to call for their fixture against Brighton on Sunday to be postponed after they were forced to call off Thursday’s game at home to Rennes. Organisers have been aware of the possibility of vaccine passports for some months, with the addition of negative lateral flow test results likely to make things easier. But there will be broader concerns over accurate verification, and also over the staffing levels needed to enforce the regulations. The rugby union Champions Cup has already been put under pressure by the Omicron outbreak, with competing squads quarantined in South Africa after positive tests. Next weekend in the second round of the tournament Bath v La Rochelle, Harlequins v Cardiff and Leicester v Connacht are scheduled to take place, with new requirements for foreign travel now in place. The Premiership has not run trials on Covid passes. The Premier League has made clear since the summer that it is well prepared for the measures, with the hope that effective implementation would limit the possibility of crowds being excluded from stadiums again should the pandemic continue to get worse. A further ban on crowds would be the worst outcome for organisers. Many professional sports teams went 14 months without being able to perform in front of crowds and the attendant drop in revenues caused a financial crisis in British sport that continues to reverberate.