Over 500 nurses have left Slovak hospitals after their mass resignation notices became effective, Health Minister Viliam Cislak announced on February 1.

The action comes less than two months ahead of elections and appears a clear bid to put pressure on the ruling Smer party as it looks to ensure a second single-party majority. Prime Minister Robert Fico has focused his campaign on the migrant crisis, successfully distracting attention from issues such as healthcare and education. Slovak teachers called a wide scale strike last week.

The nurses resigned as a sign of protest against a recent amendment to the law on healthcare. The legislation does not respect demands that wages should be reassessed every three years, nor that they should be calculated based on years of practice, the Slovak Spectator reports. The highest number of resignations came in Zilina and Presov.

"A total of 540 nurses have left our hospitals," Cislak said, according to TASR news agency. "As a human being I feel sorry, but I also need to underline that health care is being fully provided to all patients, even those in Zilina and Presov regions. We provide adequate health treatment, safe for patients."

The health minister announced he has filed a criminal complaint against the nurses for spreading "alarming" claims of threats to 1mn patients as a result of the walk outs. 

"The arrogance of power, which we have faced in recent days and weeks, only works to strengthen our conviction that our choice was right," nurse chamber president Iveta Lazorova said in response. "It's necessary to expose the dysfunctional nature of the system. We're convinced now more than ever that the solution we've embraced is the only way to go."

Corruption in the healthcare system has been a hot political issue for Smer. In 2014, Pavol Paska, Smer's second-in-command - was forced to resign following a scandal related to a shady tender at a provincial hospital. The health minister was also sacrificed as protesters rallied in Bratislava. Cislak has already survived two no-confidence votes connected to claims of corruption from the opposition.