“On January 27, I will vote. I hope so will the majority of my compatriots because this is not only an expression of opinion on the issue at hand - we will also demonstrate responsible behavior by European citizens who are able to determine their own future,” the king said.

Bulgaria's center-right Citizens for European Development of Bulgaria, GERB, government scrapped the Belene project in March 2012, declaring it economically unfeasible. The pro-Belene Bulgarian Socialist Party, BSP, then launched a petition for a referendum on the Russian-Bulgarian project.

Discussions renewed recently on the abandoned project, with Rosatom subsidiary Atomstroyexport upping its claim against Bulgaria's National Electricity Co. to 1 billion euros and a mysterious investment fund emerging with an offer to take over the project.

Bulgaria’s right-leaning Blue Coalition has challenged the legality of such a referendum.

The voters will receive a white ballot with the question "Should atomic energy be developed in Bulgaria through the building of a new Atomic Plant?" There will be an option to choose "yes" or "no" by using a blue ink pen.

Under current legislation in order to have a valid referendum at least 4 345 500 people must cast a ballot which is equal to the voter turnout at the last general election. A positive answer to the question of the referendum requires 50 percent of the vote plus 1 ballot.