Debate is raging in the U.K. over the use of COVID passports for entry into gigs and other events, which the government has yet to confirm will become a legal requirement.

Not all such public programs are currently asking customers to show their NHS pass, which provides proof of vaccination, immunity or a negative test; some are conducting spot checks for the three options, some are not and others, like The O2 Arena and Boardmasters, are asking to see the pass, which is currently a government recommendation rather than a legal requirement.

However, a new government mandate proposes that COVID passports be brought in for nightclubs and mass gatherings beginning at the end of September. As a result, the Night Time Industries Association (NTIA) says businesses are predicting a drop-off in trade of up to 30%, with ticket sales stalling from October onward.

NTIA CEO Michael Kill says more than 15k letters opposing the move have been sent to MPs by business owners, creatives, freelancers and customers; they explain the impact passports might have on the workforce, trade and culture. “After a short period of freedom, we are once again overshadowed by uncertainty. The end of September brings with it some huge challenges around staffing, discrimination, safety and tourism,” Kill said.

The move toward passports could exclude those who don’t have an NHS number, including migrants, the unhoused and people suffering housing insecurity, members of the Roma community and those in marginalized groups. Supporters of the proposed mandate point to public safety and how stringent rules for entry will help keep the live-music sector open.

In July Prime Minister Boris Johnson said that only fully vaccinated people will be able to enter venues and some events starting at the end of September, but a recently leaked letter indicates that a final decision has yet to be made. The U.K. live industry isn’t expecting the plan to go ahead, with many in the sector insisting that the current, three-option entry scheme is working well.

Those in favor of the vaccination mandate cite a recent outbreak at Boardmasters, where 4.7k cases of COVID-19 were recorded among the 50k attendees. The majority of those infected were aged 16 to 21, one of the groups with the lowest levels of vaccine uptake.