LUXEMBOURG (AP) — European Union foreign ministers say Poland must answer questions about rule of law amid concerns about a government clampdown on the independence of the judiciary.

Dutch Foreign Minister Stef Blok said Tuesday that "the rule of law is one of the backbones of European cooperation and there are a number of laws in Poland that raise questions."

Bloke says "the possibility that verdicts can be actually brought into doubt for a period of 20 years is quite unique."

The EU Commission has launched a rule of law procedure against Warsaw over what it sees as an erosion of independence in Poland's justice system.

Technically, the procedure could strip Poland of EU voting rights but this is unlikely to happen as its ally Hungary appears ready to veto such action.