An outdoor cinema screening that is part of a national pilot, exploring how mass events can take place safely, has been postponed.
The Luna Cinema was due to host the viewings, without social distancing, in Liverpool for the next three days.
It was recently targeted by anti-vaccine activists for taking part in the trial, even though attendees do not have to show proof of vaccination.
Organisers said the delay was due to "circumstances beyond our control".
Three screenings will now take place near the city's Exhibition Centre between 14 and 16 May.
They are part of the nationwide Events Research Programme, where scientists will examine the risk of coronavirus transmission from attendance at stadiums and venues.
The pilots will be used to provide data on how events can resume safely.
One of the other trials saw Wembley Stadium hosting 4,000 fans during Sunday's FA Cup semi-final.
Liverpool City Council said the cinema pilot would not be trialling vaccination certification, where people must show if they have been vaccinated, recently tested negative or have natural immunity after having Covid.
At the May cinema screenings, there will be no social distancing and people will not be obliged to wear masks.
Participants are encouraged to take a test on the day of the event and five days afterwards to ensure any transmission can be monitored.
The Luna Cinema event organiser said they had received hundreds of abusive messages from people accusing them of being part of a vaccine passport scheme after activists circulated organisers' personal details.
Liverpool's Hot Water Comedy Club pulled out of the pilot after it also received abuse over inaccurate reports that it was involved in a vaccine passport scheme.
Critics of vaccine passports said they could be "divisive and discriminatory".