The election follows the resignation of centre-left Prime Minister Miro Cerar in March and will take place only a week or two before the election would have been held if Cerar had not stepped down.
The president will hold final informal talks on the date of the election with heads of parliamentary groups and sign off on the date on Saturday, the president's office said.
Cerar resigned after the Supreme Court annulled the result of the September referendum that backed the government's key investment project -- a new railway line between the port of Koper and the city of Divaca -- and ordered a new referendum on May 13.
Latest opinion polls indicate the centre-left List of Marjan Sarec, which has never before run for parliament, could win the election ahead of the main opposition party, the Slovenian Democratic Party.