Boomtown Fair festival has been cancelled, with the organisers blaming the government for not offering COVID cancellation insurance.
The live music and theatre event, with a capacity of 66,000, sold out in February and was due to take place near Winchester in the South of England from 11-15 August.
Boomtown organisers said in statement: "We have been doing everything within our power to try to find a solution to the mind-boggling conundrum of putting on a safe and well-run event to the sheer scale, complexity and intricate nature of Boomtown this summer.
"With less than four months to go until the event, and after almost half a year of collective campaigning to the government, sadly COVID specific cancellation insurance for events simply does not exist at this point in time.
"This means anyone putting on an event this year, will be doing so without the safety net of insurance to cover them should COVID prevent them from going ahead in any capacity.
"For an independent event as large and complex as Boomtown, this means a huge gamble into an eight-figure sum to lose if we were to venture much further forward, and then not be able to go ahead due to COVID."
Boomtown Chapter One: The Gathering is now planned to take place between 10-14 August 2022, with tickets promised to roll over until next year.
Strategy director Anna Wade tweeted: "This has been a really hard decision, but without the safety net of insurance, it was sadly inevitable. Huge love to all in our beautiful industry struggling to see how we can bring people together safely this summer without risking the future of their events."
The resale for Boomtown Fair 2021 will go ahead on 1 June, for those who wish to secure tickets for next year.
The five day festival launched in 2009 and is held in the grounds of the Matterley Estate in South Downs National Park in Hampshire.
The line-up for 2021 had been kept a secret but previous headline acts over the past 11 years include Lauryn Hill, Gorillaz, Madness and The Specials.
Boomtown 2020 was also cancelled due to the coronavirus pandemic, like many music festivals, including Glastonbury.
Emily and Michael Eavis announced in March that Glastonbury 2021 will be held as a livestream event.
Coldplay, Damon Albarn, Haim, Idles, Jorja Smith, Kano, Michael Kiwanuka and Wolf Alice will perform live at Worthy Farm in Somerset on 22 May, with tickets being sold for would-be-festival-goers to watch live at home.
Watch: Glastonbury 2021 will be virtual livestream event