Bratusek's nomination was confirmed on Thursday night at a leadership meeting of the PS, which has 28 deputies in the 90-seat Slovenian parliament.
Bratusek said she would begin on Friday talks on the new government's programme with three parties that were willing to support her nomination, with the goal of giving a no-confidence vote in incumbent PM Janez Jansa. These are the Civic List, the Democratic Party of Pensioners, and the Social Democrats.
Bratusek and those three parties recently agreed on the formation of a new parliamentary majority, provided that Ljubljana Mayor Zoran Jankovic resign as PS president over a corruption scandal. He signed a decision to that effect on Thursday which would go into force with the appointment of a new government.
If the four parties manage to agree on the interim government's programme, Bratusek's nomination could be put forward in parliament next month. If she gets the majority vote, the Jansa cabinet would automatically become a caretaker government and Bratusek would have two weeks to nominate her ministers, which would require another vote.
According to the media, there are many open questions given the programme diversity of the four parties, some of which would prefer the political crisis to be solved with the fall of the Jansa cabinet and early elections.