The co-founder of Kendal Calling has criticised a 'lack of guidance' from the UK Government following a scheme to trial the return of large sale events.
Andy Smith said the festival industry continues to be 'kept in the dark' following the Government's Events Research Programme.
The ERP covered nine sporting and cultural events taking place in April and May.
There were 14 positive Covid-19 cases among more than 40,000 people who attended sporting events. However, a report on the first phase of the ERP said the figures on cases related to the events should be treated with "extreme caution".
It cited the necessarily limited scale of the events, the low prevalence of coronavirus at the time and, most crucially, the low rate of return for PCR tests before and after the events.
In all, 28 positive cases were linked to the nine events, with 58,000 people attending.
The report said it was "hard to know" if the positive post-event tests were the result of transmission at the event, and that the poor PCR return rate "significantly limits" the evidence of direct transmission at events.
The report said 11 of these individuals were "potentially infectious at an event", with a further 17 potentially infected at or around the time of the event.
This week the decision was made to cancel Kendal Calling for a second year running.
Co-Founder of the Cumbrian music festival Andy Smith cited a lack of Government guidance for the tough call:
"The research has been published but there is still no accompanying guidance. It is this lack of guidance which this week caused the cancellation of Kendal Calling, Truck and a host of other festivals and events large and small."
"It is currently impossible to plan or budget for an event whilst we continue to be kept in the dark in this way. We once again ask the Government - where is the guidance? It is too late for us but prompt intervention can save the summer for others."
The report into the Events Research Programme also highlighted that even with entry being conditional on proof of a negative lateral flow test within 36 hours of the event, some potentially infectious people will still be admitted.
This, the report says, indicates "a need for robust outbreak control procedures to be in place".
The Government said there are "live discussions" going on with a view to adding further events to the third phase, which will focus on certification via proof of a negative test or full vaccination.
Sports clubs and governing bodies are keen to see what the Government will announce ahead of the scheduled final easing of restrictions on July 19, but the ERP report simply stated:
Currently, events not included in the ERP are operating to strict attendance limits.
For outdoor venues with a seated capacity of 16,000 or above, the limit is 10,000 or 25 per cent of capacity, whichever is lowest.
For outdoor venues with less seating than that, the limit is 4,000 or 50 per cent of capacity, whichever is lowest.
For indoor venues, the limit is 1,000 or 50 per cent capacity, whichever is lowest.
Responding to the live events pilot report, Mark Davyd, chief executive of the Music Venue Trust, said: "As widely leaked, the results of the ERP test events demonstrate that the average live music event, even with thousands of attendees, presented no assessable significant additional risk of infection above that which can be found spending six hours at an average office.
"The tiny number of cases, and almost insignificant number of possible transmissions, was in line with what everyone expected to see at a well-managed, professional event. We have 950 grassroots music venues with small capacities ready to run well managed events.
"Everyone wants to reopen those venues safely. The Government mantra is data not dates. The data says we can do this safely on July 19."