England's hopes of hosting up to 20,000 fans at Twickenham against the Barbarians are in serious jeopardy as Downing Street considers a short-term "circuit break" lockdown.
The RFU had retained some hope of getting permission to host the largest number of fans so far at a UK sports event since lockdown despite Boris Johnson last week announcing a review around the timetable for the return of crowds.
However, potential nationwide measures said to be likely during the October half-term would throw the autumn internationals into chaos.
Tickets for the match against the Barbarians on Oct 25 went on sale a fortnight ago, with England slated to travel to Rome to take on Italy in the delayed Six Nations contest a week after the encounter. England are back at Twickenham to play Georgia on Nov 14.
Subject to obtaining the relevant approvals, including those from public health authorities, spectator numbers will be up to 20,000; less than 25 per cent of the stadium's total 82,000 capacity.
The RFU must still receive a rubber stamp from the Government to be able to allow such high numbers into Twickenham, but the English governing body insisted it already has strong social-distancing plans in place. "The number of fans allowed into Twickenham Stadium for the fixture is based on social-distancing requirements to mitigate against the risk of Covid-19 transmission," read an RFU statement.
Nicola Sturgeon and Sir Keir Starmer have asked Boris Johnson to convene a Cobra meeting this weekend, for the first time after several months.
Swathes of the North West, Midlands and West Yorkshire have been hit with tougher Covid restrictions to curb rising rates of infection. The new rules, which will come into force from Tuesday and affect more than three million people, prohibit socialising between households in gardens and homes in Merseyside, much of Lancashire, Bradford, Kirklees, and Wolverhampton.