The anti-immigrant SDS party of veteran right-wing leader Janez Jansa won Slovenia's parliamentary election, but now faces a difficult task in courting a coalition partner to govern.

The centre-right Slovenian Democratic Party secured 25 percent of the vote, the State Election Commission said late on Sunday.

The anti-establishment LMS party of comedian-turned-politician Marjan Sarec had 12 percent, followed by the centre-left Social Democrats with 10 percent, and the SMC party of outgoing Prime Minister Miro Cerar at 9 percent.

The results mean a coalition government will have to be formed because no party achieved a majority. 

In a statement after polls closed, Jansa, 59, said he was committed to forming a government "for the good of all our citizens" and to ensure a "safe Slovenia".

Sarec said he also expects to be in position to form the government and is ruling out a coalition with Jansa. Most parties said before the vote they were unlikely to join an SDS-led government because of its harsh stance towards migrants.