Croatian President Zoran Milanovic declared his candidacy for prime minister in the upcoming parliamentary elections at a press conference alongside opposition Social Democratic Party (SDP) leader Pedja Grbin on March 15. 

Croatia's prime minister has significant policy-making authority. The president, meanwhile, has the right to nominate the prime minister based on election outcomes and influences foreign policy as the armed forces chief. 

Milanovic, backed by the SDP for the presidency, has an acrimonious relationship with current Prime Minister Andrej Plenkovic and the ruling Croatia Democratic Union (HDZ). The two have clashed repeatedly, including over Croatia’s foreign policy and stance on the war in Ukraine. 

On Facebook, Milanovic expanded on his plans to resign from the presidency if elected prime minister. 

Running as an independent candidate on the SDP list, Milanovic expressed confidence in his electoral prospects and pledged to make the transition seamlessly from the presidency to leading the government. Previously, Milanovic was Croatian prime minister between 2011 and 2016.

"After winning the elections, which I am convinced I will do, I will resign from my office as President of the Republic," he said, according to an SDP press release.

"We will throw out thieves, oppressors and their helpers and prevent their return, but this time for a long time," he said, painting a vision of a fairer Croatia where "rivers of justice will flow in the spring”. 

HDZ politicians slammed Milanovic’s decision to run for prime minister, calling it unconstitutional. 

Recent polls show that the ruling HDZ is in the lead, followed by the SDP. 

Plenkovic announced earlier this month that the parliament would be dissolved to pave the way for a general election before the European Parliament elections scheduled for June. He was widely expected to opt for a spring election, rather than a date closer to September 24, the deadline for Croatia to hold its next general elections. 

Milanovic has now officially picked the date for the parliamentary elections, which will take place on April 17. Milanovic's decision, outlined in a statement from the presidency, comes after the dissolution of the Croatian parliament. 

The decision on calling for the election of representatives to the Croatian parliament entered into force on March 15.

The election will be held at polling stations across Croatia, with diplomatic and consular missions also participating in the process. April 17 will be designated as a non-working day in accordance with electoral regulations.

Milanovic has also announced the election for members to the European Parliament from Croatia. The election is scheduled to take place on June 9, at polling stations across Croatia and at the diplomatic and consular missions of Croatia. This decision will come into effect on April 9, as stated by Milanovic.