The European Public Prosecutor’s Office warned last month that restricting protection for whistleblowers “seriously limits detection, reporting, and investigation, particularly of corruption.”

The Slovak decision, which drew 78 votes in the 150-seat parliament, is expected to spark tensions with the European Commission. The EU executive noted last month that “several elements of this law raise serious concerns in relation to EU law.”

“We regret that MPs did not heed the warnings of dozens of experts and international organizations, including the European Commission and the European Public Prosecutor’s Office, which drew attention to the negative impacts of the new law,” the Slovak whistleblower office said in a post on Facebook.

“The level of protection, as well as public trust in the whistleblower protection system that we have painstakingly built at the office over the past years, will be significantly weakened by this law,” it added.

NGOs and the political opposition said they view the move as political payback from Interior Minister Matúš Šutaj Eštok, whose ministry had been fined by the whistleblower office for suspending elite police officers under whistleblower protection without first notifying the office. The suspended officers had been investigating corruption among senior Slovak officials.

Slovakia’s Interior Ministry told POLITICO in a statement that “the opposition’s claims of ‘revenge’ are false and have no factual basis.”

“The change [with the office] is not personal, but institutional. It is a systemic solution to long-standing issues that have arisen in the practical application of the current law, as confirmed by several court rulings,” the ministry said, adding that the changes are consistent with the EU’s whistleblower protection directive.