The existing law will remain in force until July 1, 2021. Before that date, the Seimas will have to pass a constitutional Law on Referendum.
The current law was passed in 2018 by a simple majority of votes in the presence of a quorum, the usual procedure for adopting new legislation.
The Law on Referendum is on the list of constitutional laws approved by the Seimas in 2012.
Therefore, a group of MPs said the procedure for adopting a constitutional law had to be followed and asked the court to look into the matter.
Under the Constitution, at least 71 members of the 141-strong Seimas must vote in favor to adopt a constitutional law and at least a three-fifths majority of votes is required to amend it.
The Law on Referendum was passed in December 2018 with 65 votes in favor, two against and 18 abstentions.