The SDS gained almost five percentage points on the month before to 13.7%, while the SMC lost four points to 12.4% and the opposition United Left (ZL) edged 1.3 points higher to 8.5%.

The coalition Social Democrats (SD) polled at 6.4%, down from 7.2% a month ago, followed by the now non-parliamentary People's Party (SLS) at 3.9%, the coalition Pensioners' Party (DeSUS) at 3.5% and the opposition New Slovenia (NSi) at 2.9%.

According to Delo, the steady fall in the SMC's rating is reflected in an increase in the proportion of those who would not vote for any party to 21% from 13% in November and 9% in October.

A further 10.2% were undecided and 14% said they would not turn out.

The approval rating for the government fell to 2.49 on the scale from one to five, from 2.58 in November. The government now enjoys the support of 22.5%, while 53% disapprove of it with 18% in between.

The National Assembly's score improved slightly to 2.34 from 2.31 in November.

The most popular politician remains President Borut Pahor ahead of Slovenia's former European Commissioner Janez Potočnik and Agriculture Minister Dejan Židan, the leader of the SD.

Meanwhile, PM Cerar fell to fourth spot from second in the past two months. He topped the rankings after the 13 July general election.

The poll was carried out by Delo Stik between 1 and 4 December among 600 adults.