VIENNA • Several top Austrian conservatives have urged voters to shun far-right candidate Norbert Hofer in next month's presidential election, highlighting fears he could take the country out of the European Union.

In a manifesto, senior conservatives, including former EU agriculture commissioner Franz Fischler and former vice-chancellor Wilhelm Molterer, both from the People's Party (OeVP), said the next president must be "dependable".

To protect its economic vitality, "Austria must remain a trustworthy European and international partner", they wrote. The manifesto published on Saturday offered support for Mr Hofer's liberal rival the independent Alexander Van der Bellen.

Mr Hofer, who heads the far-right Freedom Party (FPOe), has not ruled out a referendum on Austria's future in the EU following Britain's shock vote in June to quit the grouping.

"We do not want to be faced with speculation about Austria leaving the European Union nor with attempts to hide the cornflower behind a crucifix," the declaration said, referring to a recent controversy.

The 45-year-old has been accused by Christian groups of manipulation after he added the phrase "So help me God" to his campaign posters. He has also been criticised for wearing a cornflower, a blue flower with a controversial past which was used by banned Austrian Nazis in the 1930s to identify each other. Mr Hofer has insisted he wore it only for the blue - the colour of the FPOe.

Like populist parties elsewhere in Europe, the FPOe is currently leading national polls.

Mr Hofer, hoping to become the EU's first far-right head of state in the Dec 4 poll, has been stoking public fears about rising unemployment and record immigration.

Austria - a nation of 8.7 million - has taken in more than 120,000 migrants from the Middle East, Africa and Asia since last year, bearing much of the burden of the influx together with Germany and Sweden. This left many Austrians angry about the EU's failure to find joint solutions to the issue.

The manifesto said Austria's president must be a guarantor of co-existence and "that is incompatible with speeches about fear, hate and the constant search for scapegoats".

The OeVP has not given its followers official voting recommendations but many of its senior members have already said they would back Mr Van der Bellen.

The 72-year-old former Green Party leader and university professor ran against Mr Hofer in May, winning by a narrow margin. But the result was later dramatically overturned by Austria's highest court which upheld claims of procedural irregularities brought by the narrowly defeated far-right.

Opinion polls suggest the outcome of the re-run is too close to call. Political analysts say that if Mr Hofer wins the presidency, this could lead to early parliamentary elections and an end to the centrist, pro-European coalition that has dominated Austrian politics for decades.

AGENCE FRANCE-PRESSE, REUTERS