Poland’s political establishment must open up negotiations on proposals to reform the country’s courts to avoid further damage to the country’s judicial system, a United Nations envoy urged on Friday.

Secrecy surrounding the proposals, if not dispelled, could do lasting harm to Poland’s court system, said Diego Garcia-Sayan, a UN special rapporteur on the independence of the judiciary.

The proposed changes “risk hampering the capacity of judicial authorities to ensure checks and balances and protect and promote human rights,” Garcia-Sayan said at a briefing after a four-day mission to Warsaw.

Poland’s ruling Law and Justice (PiS) party is embroiled in a confrontation with President Andrzej Duda over reforming the court system.

The standoff began in July, when the president, a PiS ally, unexpectedly vetoed bills that would have changed the makeup of the Supreme Court and how judges are chosen.

PiS says the judicial system needs to be reformed because the courts are slow, inefficient and steeped in a communist-era mentality. But critics of the plans say they are part of a drive toward authoritarianism.

Jaroslaw Kaczynski, the leader of PiS and Poland’s paramount politician, has since met privately with Duda four times for talks on the reforms. Details of those meetings have been kept secret, and it is not known whether a consensus is in sight.

Garcia-Sayan said it was difficult to understand how in a democracy work on major legal reforms could take place behind closed doors.

“It’s not a technicality that’s being discussed, but a major thing that will have to do with justice, checks and balances, and so on,” he said. “So, a major suggestion is, please, open political, substantial dialogue.”

He added that the judiciary reform that PiS has been pushing since coming to power in late 2015 has been presented as a cure, but “appears to be worse than the disease affecting the Polish judiciary.”

Garcia-Sayan’s comments were “not supported by facts” and were “harmful for Poland and the Polish people”, Rafal Bochenek, a government spokesman, told Poland’s state news agency, PAP.