Hundreds of Polish nurses who are seeking pay rises remained camped outside the prime minister's office on Monday, and warned they would stay put for weeks unless the government gives ground.
The nurses first pitched camp on a grass verge opposite the government headquarters on June 19, in the wake of a demonstration by 4,500 medical workers.
They have informed Warsaw city hall that they plan to keep up the high-profile protest until August 15, unless they get a hearing, said Halina Teplinska, an official of the OZZPP nurses' union, quoted by Poland's PAP news agency.
Talks between the government and the OZZPP have failed to get off the ground, with each side accusing the other of bad faith.
Government spokesman Jan Dziedziczak said that Prime Minister Jaroslaw Kaczynski would not begin negotiations unless four nurses ended their occupation of a room in the government's office, which they began last week after receiving permission to hand over a petition.
Nurses' delegates said that the four would not budge, because they were simply waiting for Kaczynski to meet them so they could give him the petition.
Kaczynski accused the occupying nurses of breaking the law and signalled that they could face trouble.
"This is an offence. A public official is under the obligation to inform justice authorities if he is aware of an offence, and we will be forced to do so," Kaczynski told reporters.
Kaczynski has instead proposed talks at another venue with several medical unions, something the OZZPP has resisted because it claims it is a government ruse to water down protests by different branches of the health service.
Kaczynski's conservative government is already facing a go-slow by hospital doctors, who since May 21 have been refusing to provide all but emergency medical services or carry out administrative duties.
The OZZL physicians' union has threatened to launch a hunger strike unless the government gives in to its demands for a massive pay hike.
Medical workers also protested elsewhere in Poland Monday.
In the southern city of Krakow, several hundred doctors and nurses held a street demonstration before handing regional governor Maciej Klima a petition for Kaczynski.
"I'm a doctor myself, and I'll be your advocate," Klima told them, according to PAP.
A similar demonstration took place in Katowice, in the heart of Poland's Silesian industrial region.
Poland's state-employed medical workers are notoriously overworked and underpaid, like their counterparts across most of the former communist bloc.
Polish nurses earn the local equivalent of 290-340 euros (390-450 dollars) a month, while the average pay packet for hospital doctors is 395 euros.
The government has said that Poland lacks the budget to grant health workers major pay hikes.