Mr Jansa’s Slovenian Democratic Party (SDS) won 25 percent of the 99.9 percent of votes counted and came out victorious with 25 seats in parliament yesterday but accepted he could struggle with coalition talks.
The 59-year-old said: “We will probably have to wait for some time before serious talks on a new government will be possible.”
He later told reporters “The SDS is open for cooperation” adding “times ahead will require cooperation”.
The centre-left LMS party, led by social satirist Marjan Sarec, came in second with 12.7 of votes and 13 seats, Politico reports.
The Social Democrats were third in the poll having acquired 10 percent of the votes winning the same number of seats.
The election in Slovenia, home of Donald Trump’s wife Melania, was brought forward by a week after after Prime Minister Miro Cerar of the Modern Center Party quit after a referendum annulment on a multi-million government rail project that triggered dire relations with his coalition partners.
Mr Cerar came forth in the ballot with 9.75 percent of votes and 10 seats in parliament.
Mr Jansa’s drive for power comes almost 30 years to the day after his arrest for spreading military secrets which played a part in the break-down of communist Yugoslavia, which made up a cluster of eastern European countries including Slovenia.
Mr Jansa, who has a liberal background, won his party seats in parliament after getting tips from Hungarian prime minister Viktor Orban’s political playbook.
The SDS leader’s success with Slovenia’s two million voters further excels the country’s growth of right-wing populism and drive for tougher anti-immigration rules.
Mr Orban has continually been a thorn in the European Union’s side and a constant critic of the bloc’s migration policies.
Some 500,000 migrants from the Middle East and Africa passed through Slovenia during 2015.
The turnout was 52 percent, which is on par with the country’s 2014 poll, but lower than in 2011 when it was reported as 66 percent.
Up to 20 political parties have competed for leadership.