The Finnish theatre sector has called on the government to abolish the requirement that audience members must be seated at least two metres apart.
It said this means that theatres can only take in 10-20 percent of their audience capacity, in effect meaning that performances cannot be financially viable.
The statement, published on Saturday, was backed by more than 100 groups in the theatre industry.
According to the open letter, the two-metre safety distancing requirement for indoor events makes theatrical operations financially "absurd", as operating costs remain the same as when presenting to a full auditorium.
Coronavirus passport needed urgently
Instead, the theatre industry urges that coronavirus passports be introduced as soon as possible to allow audiences to attend cultural events safely this autumn.
On Thursday, the government decided to continue preparations for the possible introduction of a coronavirus passport. So far, there is no information on when the passport could be made available. Ministers say it must be approved by Parliament, which does not reconvene until 7 September.
The letter argues that as long as there are restrictions on public events, the industry will generate losses and need additional state support for both theatres and freelancers, including rising unemployment benefits.
Losses in the performing arts sector are around 1.5 million euros each week, according to the daily Helsingin Sanomat.
The statement was released on Saturday at the Tampere Theatre Festival.
The signatories include the Association of Finnish Theatres, the Finnish Theatre Directors' Association, the Finnish Actors' Association, the Finnish National Theatre and the Helsinki City Theatre.