Hungary will hold a referendum in September or early October on whether to accept any future European Union quota system for resettling migrants, the prime minister's office said on Tuesday.
Prime Minister Viktor Orban has taken an increasingly anti-immigrant stance since the migration crisis escalated last year and opposes a plan, agreed by a majority of EU governments in September, to redistribute 160,000 migrants around the bloc.
Along with Slovakia, Hungary has launched a court challenge against that plan, which will set quotas for each EU country to host a share of the migrants over two years.
The referendum will ask Hungarians whether they would accept any permanent quota system beyond that.
The question voters will be asked is: "Do you want the EU, even without the approval of Hungarian parliament, to be able to prescribe the mandatory resettlement of non-Hungarian citizens in Hungary?"
"There are crazier and crazier ideas coming up in Brussels. It seems that Brussels has not given up on the plan for mandatory resettlement," Antal Rogan, Orban's cabinet chief, told a news conference.
Once parliament approves holding the referendum, President Janos Ader will set a date on the matter that Rogan said was an "issue of national sovereignty".
Hungary has erected a steel fence along its southern border to stop migrants and refugees, many of whom arrive in Greece fleeing war in Syria, Iraq and Afghanistan, and try to travel north to settle in countries such as Germany and Sweden. Several other countries in southeastern Europe have also put up fences.