According to the document, a former Constitutional Court judge and opposition lawmakers have said a proposal to hold a dual citizenship referendum on two days with a gap of two weeks between them may run counter to the constitutional principle of equality of people, because those voting on the second day will have more information about the plebiscite than those voting on the first day.
Širinskienė says all doubts about the constitutionality of the referendum and the legitimacy of its results must be dispelled before the plebiscite.
The Seimas is currently debating a draft resolution to hold a dual citizenship referendum on May 12 and 26, in tandem with the first and run-off rounds of the presidential election.
The Constitution currently does not allow a Lithuanian citizen to be a citizen of another state at the same time, except in individual cases provided for by law.
If approved in a referendum, the proposed constitutional amendment would come into force on January 1, 2020.