Austria's presidential election has been left poised on a knife-edge after initial exit polls showed far-Right candidate Norbert Hofer leading by the narrowest of margins as polls closed on Sunday evening.

Exit polls from Austria's state broadcaster showed Mr Hofer, the far-Right Freedom Party (FPO) candidate who comfortably won last month's first round vote, on just 50.2 per cent.

The result will be a disappointment for Mr Hofer, a 45-year-old aviation engineer who is threatening to become the first far-Right head of state in the history of the EU, a result that could send political shockwaves through Europe.

His tally was less than half a per cent ahead of his opponent Alexander Van der Bellen, a 72-year-old retired political science professor and Green Party politician who ran as an independent.

Mr Van der bellen scored only 22 per cent in the first round, comfortably behind Mr Hofer's 35 per cent, but looks to have taken advantage of tactical voting among establishment and liberal Austrians determined to stop a far-Right presidency.

Election analysts said the final outcome would be decided in the cities of Vienna and Salzburg which are likely to favour Mr Van der Bellen over Mr Hofer, whose anti-immigrant, anti-austerity platform appeals Austria's small towns and villages.