Voters are being asked whether or not to accept EU quotas for migrants and refugees rather than whether they should continue to be members of the EU itself.

The question on the ballot is: "Do you want the European Union to be entitled to proscribe the mandatory settlement of non-Hungarian citizens in Hungary without the consent of the National Assembly (Parliament)?"

Despite not being a referendum on membership itself, it could follow Brexit in further exposing fault lines across the continent.

Hungary's right-wing and nationalist Prime Minister, Viktor Orban, who is regarded as a renegade by some fellow EU leaders, has called on his citizens to vote "no" in the ballot.

Mr Orban wants Hungarians to reject the EU quota system designed to share the burden of the migrant influx by distributing successful asylum seekers evenly among European countries.

"For us migration is not a solution but a problem ... Not a medicine but a poison. We don't need it and we won't swallow it" Mr Orban said earlier this year.

"Every single migrant poses a public security and terror risk," he said.

The government's campaign to ensure a "no" vote has cost close to €35m.

Government posters and billboards displayed access the country say: "Don't risk it - vote no".

They all begin with the word "Tudta?", Hungarian for "Did you know?"

One says: "Did you know? Last year one and a half million migrants arrived in Europe."

Another reads: "Did you know? Since the immigration crisis in Europe more than 300 people have died in terror attacks."

What the poster campaign lacks in context, it makes up with in emotionally charged sentiment.

"Did you know? The Paris attacks were carried out by immigrants" another reads, despite the fact that the known Paris attackers were actually EU citizens.

They were raised in France and Belgium though some had posed as refugees when returning from trips to Syria.

Hungarian PM Viktor Orban casts his vote in the referendum as his wife Aniko Levai stands by in Budapest | Photo: PA Images

Securing borders

Hungary found itself at the centre of the 2015 migration crisis, with tens of thousands of refugees and migrants trying to pass through the country to reach Northern Europe.

Budapest's Keleti train station was a bottleneck with migrants - most from Syria, Iraq and Afghanistan - trying to board trains bound for Munich in Germany.

Hungarian government policy was first to push them back, then let some through and then to build a fence to stop more from coming.

The government says its migration policy is the only consistent policy in Europe: to secure its borders and to expel illegal immigrants.

With a nationalist and pro-Christian agenda, it has rejected suggestions that it should accept the migrant quota set by Brussels.

Some say the referendum is just a ploy by Mr Orban to bolster his power with a populist agenda and divert attention away from other domestic pressures.

They argue that with a misleading poster campaign generating a fear of immigrants, Mr Orban can be seen to be strong against manufactured threats from immigrants.

In doing that, he presents himself as an anti-Angela Merkel figure on the European stage; a leader who stands against Brussels-led federalist control and, in his words, "liberal blah blah".

The result is widely expected to be a win for Mr Orban, with most voting "no".

The "yes" vote count is expected to be the smallest, with many others choosing either to spoil their ballot or not vote at all.

While not legally binding, a win for Mr Orban with a voter turnout of over 50% would prove that, in this EU nation at least, nationalism trumps liberalism.

It will be a poke in the eye for an increasingly fragile European Union.