"It was a very unpopular decision, there were some very strong reactions," Wojtasik, 50, whose Yatta Ramen eatery specialises in Japanese cuisine, told Reuters. "But not for our usual customers. They've taken it very well."

He is one of a number of businesses in Poland taking matters into their own hands, barring all unvaccinated visitors without any state mandate to do so, as new daily COVID-19 infections exceed 30,000 amidst a relatively soft government response to the pandemic compared with many other European countries.

Only about 56% of Poles have been fully vaccinated against COVID-19, well below the European Union average. Less than a third have received a third booster shot, with many regions in the south and east showing very low vaccination rates among a widely sceptical population.

Under current rules, venues such as restaurants and bars can provide up to 30% of their capacity to unvaccinated people, and with infections soaring, the government has drawn criticism from doctors for not imposing stricter curbs on social activity.

Thirteen of 17 members of Poland's Medical Council advising the prime minister on COVID-19 resigned on Friday, condemning what they said was a lack of scientific influence on policy.

Some of the advisers told Reuters they quit in part because of the government's refusal to implement rules such as those introduced in France, where customers are asked to show their vaccine certificates in restaurants, cafes and other places.

Professor Robert Flisiak, one departing adviser, said such policies were proven to raise vaccination rates. "We could increase the number of those vaccinated by 10%, which would at least help us meet the EU's average rate," he said.

He praised restaurateurs taking tougher action. "Of course they face hate and ostracism, even aggression, so of course it's very courageous of them amidst a lack of legal support from the state."

Konstanty Szuldrzynski, another departing medical adviser, accused the right-wing ruling party of pandering to a vaccine-sceptic voter base and tying the health ministry's hands.

"The government knows very well what they need to do. The fact that it isn't taking action isn't tied to bad intentions but to a lack of political support from its base."

Poland's government has said it often had to deal with opposing opinions from various bodies, not just those of its advisers. It said the council's ways of functioning would change, without elaborating.

Wojtasik, the restaurateur, said he hopes the self-imposed restrictions at his eartery will at least play a small part in limiting the harm caused by COVID-19.

"Some of my friends died, people who were younger than me. I know this (virus) is a real risk that you can't underestimate."