COPENHAGEN (Reuters) - Denmark heads to the polls on Thursday to decide whether to adopt some EU rules, testing for the first time one of the country's decades-old exemptions from European integration since Danes resoundingly rejected the euro in 2000.
The government, together with the main opposition party, argues Denmark needs to adopt some EU justice and home affairs laws to keep the country within the cross-border policing agency Europol.
But the populist Danish People's Party (DF), now the second-largest faction in parliament, says Danes should vote "No" to retain a hard-fought-for exemption won in 1993 and avoid giving away sovereignty over security to eurocrats in Brussels.
The vote comes amidst heightened security fears across Europe after the recent Paris attacks claimed by Islamic State militants which killed 130 people, and as Europe struggles with a huge influx of refugees from Syria and other countries.
Polls show opinion split evenly, if somewhat tending towards voting "No" in recent days, with a large portion of people undecided. Analysts say the "Yes" campaign has been lackluster while the "No" side had a much simpler message of rejection.
Denmark needs to adopt some EU rules because of a reform of Europol, the European Police Office, that will change the way it receives and analyses data. The ruling center-right Liberals, ex-ruling Social Democrats, and several other parties agreed on 22 EU laws that Denmark would opt into if the vote is a "Yes".
All have stressed the acts do not concern immigration, another part of the Justice and Home Affairs policy from which Denmark is exempt, meaning it does not, for example, have to participate in schemes to resettle refugees.
But the referendum asks Danes to give parliament the power to decide on the opt-ins. It does not ask Danes to approve the 22 EU laws. Analysts say that has allowed the euro-sceptic DF party to play on Danish mistrust of politicians.
DF says Europol participation can be maintained through other treaties and that there is nothing forcing future governments to conduct more plebiscites should they want to opt in to EU rules on immigration, from which Denmark is now exempt.
Denmark, Britain and Ireland all won concessions from the EU in the early 1990s when the modern foundation for the now 28-member bloc was laid. Like Britain, Denmark did not adopt the euro, and both Britain and Ireland were exempt from the passport-free Schengen area.
A "No" result would cheer Britain's anti-EU UK Independence Party, which wants a total withdrawal from the EU. But British Prime Minister David Cameron could also point to it as a sign that other nations other than Britain are unhappy with the EU as it stands today. He is trying to renegotiate Britain's relations with the EU ahead of an in-out referendum by 2017.
(Reporting by Sabina Zawadzki; Editing by James Dalgleish)