Hungary is voting in a referendum on accepting mandatory EU quotas for relocating refugees.
PM Viktor Orban opposes plans to relocate a total of 160,000 refugees across the bloc.
Under the EU scheme, announced after 2015 refugee crisis, Hungary would receive 1,294 asylum seekers.
According to opinion polls, strong support for a rejection among those who say they will vote. To be valid, turnout needs to be over 50% of voters.
During the refugee crisis, Hungary became a transit state on the Western Balkan route to Germany and other EU destinations.
In an effort to curb the influx, Hungary sealed its border with Serbia and Croatia. The measure was popular at home but criticized by human rights groups.
Voters are being asked: “Do you want the European Union to be able to mandate the obligatory resettlement of non-Hungarian citizens into Hungary even without the approval of the National Assembly?”
In December 2015, Hungary filed a court challenge against the EU plan, which would see relocations over two years.
In a TV interview on September 29, Viktor Orban said: “If there are more <<no>> votes than <<yes>> votes, that means Hungarians do not accept the rule which the bureaucrats of the European Commission want to forcefully impose on us.”
“The more refugees there are, the greater the risk of terror,” the right-wing prime minister added, according to excerpts published by Reuters.
The EU proposal was meant to ease pressure on Greece and Italy, the main entry points for refugees into the bloc.