On 3 December, Danes will vote on a 'flexible' opt-in approach to EU Justice and Home Affairs (JHA), Prime Minister Lars Løkke Rasmussen announced.
In March this year, pro-EU parties in the Danish parliament agreed that 22 legal acts would be submitted to a referendum.
Lawmakers worry that Denmark will eventually be forced to leave Europol, which the country joined 17 years ago.
These legal acts include the cross-border Legal Aid Directive, the Cyber Crime Directive, the Directive on combating the abuse and sexual exploitation of children, and the Directive on trafficking in human beings.
Ten legal acts have been excluded from the arrangement, including one on asylum and immigration policies. Rasmussen repeatedly stressed this point during a press conference on Friday.
The Danish case-based opt-in approach would be similar to the EU justice arrangements currently in place in the UK and Ireland.
As EurActiv reported yesterday, Rasmussen carefully planned to have the date for the justice affairs referendum weeks before British Prime Minister David Cameron's will announce his EU reform proposals at a summit in Brussels 17-18 December, to avoid the Danish referendum being influenced by the Brexit debate.
Following reform negotiations with the EU, Cameron has promised British voters a referendum on EU membership, which will likely take place in 2016.
Mette Frederiksen, the leader of the biggest opposition party, the Social Democrats, remarked that it will be necessary for the Danes to vote 'Yes' in December in order to secure the best working condition for the Danish police.
"We have a very skilled police force, but in order to fight cross-border crime, such as child pornography and human trafficking, we need to still be part of the Europol cooperation," she told Danish broadcaster DR.
Apart from the Justice opt-out, Denmark also holds EU opt-outs on Defence, Citizenship and the Economic and Monetary Union (the euro cooperation).