Under the law, the prime minister must notify of his resignation his cabinet and the parliamentary speaker, who has to convene a session of the National Assembly within seven days.

Parliament will likely acknowledge Cerar's resignation at the plenary, which is scheduled to start on Monday.

MPs will decide whether to expand the programme and when they will get informed about Cerar's resignation. He stepped down following the Supreme Court's annulment of the 2017 referendum on the Divača-Koper railway expansion, the government's priority.

Once Cerar's resignation is formally acknowledged, a 30-day window for the election of a new prime minister-designate opens. Nominations can be put forward by the president, deputy groups and groups of at least 10 MPs.

If a new prime minister is not appointed in this time, the president dissolves parliament and calls an early election to be held within 40 days at the earliest and two months at the latest.

It remains unclear whether President Borut Pahor will call snap or regular election, since the earliest regular election can be called is two months before four years have passed from the National Assembly's maiden session. Current parliament met for the first time on 1 August 2014.

Regardless, snap election or regular, the date of the election will not be significantly different, as Pahor was expected to call the election on 10 June before the resignation.

Pahor is to meet Cerar at noon today, when more will expectedly be clear about further steps.