Glastonbury organiser Emily Eavis has conceded that the festival may not be able to go ahead in 2021 due to coronavirus.
This year's event - intended to be a 50th anniversary celebration - was cancelled in March as the UK entered lockdown, with all ticket-holders being guaranteed entry next year instead.
Although a coronavirus vaccine is now available, the manufacturing and distribution timescales involved mean that it is likely to be towards the end of 2021 before the world is able to get back to normal.
For planning reasons, however, Eavis has revealed that she will need to make a call on whether Glastonbury 2021 can proceed sooner rather than later.
"It's been way too quiet here this year and we want to get people back here as soon as we possibly can," she told BBC News. "Obviously the vaccine news in recent weeks has increased our chances, but I think we're still quite a long way from being able to say we're confident 2021 will go ahead.
"We're doing everything we can on our end to plan and prepare, but there are still just so many unknowns and factors which are completely out of our control.
"What we definitely can't afford to risk is getting too far into the process of next year, only for it to be snatched away from us again. We lost millions this year, and we can't risk that happening again."
She added: "As long as we can make a firm call either way well in advance, then we'll be OK. The next few weeks are going to be crucial, really. They'll hopefully give us a much better idea of what is and isn't going to be possible."
The coronavirus vaccine is not expected to become available to the general population aged under 60 until several months into 2021.