Ljubljana Mayor Zoran Jankovic and his new Positive Slovenia party came top in the country's parliamentary election Sunday, in what appeared to be a stunning victory.

Jankovic's party, never before tested in elections, won 29 per cent of the votes, Slovenian state television said, citing exit polls.

A former chief executive of the nation's largest retailer, Jankovic had a strong following in Ljubljana since winning mayoral elections there in 2006.

Conservative former premier Janez Jansa's Democratic Party, who had been tipped as the almost-certain winner in pre-elections polls, came second with 26.5 and the outgoing Prime Minister Borut Pahor's Social Democrats with 10.8 per cent.

Another new party, founded by businessman Gregor Virant, came in fourth. Several other parties cleared the 4-per-cent hurdle to qualify for the parliament, according to early figures.

Early elections were forced in September, when Pahor was toppled in over an austerity package intended to deal with Slovenia's unsustainable spending.

A former Yugoslav republic that joined EU in 2004 and the eurozone in 2007, Slovenia has come under threat of a spiraling recession because of the spending and ballooning debts.

The next cabinet faces a difficult task of turning the situation by reforming the pension system, state administration and the state economy, and all of it effectively without additional borrowing.