Bulgaria's Parliament will hold an extraordinary sitting on a proposal for a referendum on election rules on Tuesday.

Parliament Speaker Mihail Mikov scheduled the extraordinary sitting for Tuesday at 2 pm.

The referendum proposal was initiated by Bulgarian President Rosen Plevneliev and was backed by an initiative committee.

The referendum questions proposed by Bulgarian President Rosen Plevneliev concern the opportunity to introduce majority voting for a part of the Members of Parliament, as well as compulsory voting and electronic voting for elections and referendums.

The MPs from ruling party The Bulgarian Socialist Party (BSP) are most likely to insist that the three referendum questions be reviewed separately so that they can back the proposal for compulsory voting, according to reports of dnevnik.bg.

Nationalist party Ataka has also expressed support for compulsory voting but it opposes a referendum on all of the three questions.

Center-right party GERB (Citizens for European Development of Bulgaria) approves the proposal of Plevneliev in its entirety and insists that the referendum be held together with the early elections.

Liberal party Movement for Rights and Freedoms (DPS) firmly opposes the referendum.

Bulgaria's Parliament is under an obligation to decide on the referendum proposal due to the petition backed by 560 000 signatures.

Although a subsequent inspection declared over 100 000 signatures to be invalid, Bulgarian law obliges the Parliament to discuss the proposal and come up with a decision on it in the case of a petition backed by over 200 000 signatures and to hold a referendum in the case of a petition backed by over 500 000 signatures.