Slovakia's president on Wednesday set Sept. 18 as the date for a referendum on cutting parliament's size by a third and on five other questions aimed at reducing costs and improving political transparency.
A majority of voters in the country of 5.4 million must take part for the vote to be valid.
Only one of the euro zone member's six previous plebiscites has been valid -- 52 percent of Slovaks took part in the 2003 vote approving their entry into the European Union.
Initiated by the liberal Freedom and Solidarity (SaS) party, which is due to form a cabinet this week with three other centre-right parties, the main motion seeks to cut the size of the chamber to 100 deputies, from 150 now, as of 2014.
SaS' coalition partner, the mostly ethnic Hungarian party Most-Hid, supports the referendum. But the centre-right SDKU party, led by Iveta Radicova, who will be named prime minister on Thursday, has been lukewarm in its support.
The vote also includes questions on whether national elections can be held by internet and whether or not to eliminate fees for state television and radio.