Voters in Portugal are heading to the polls to choose their next president in an election being closely watched in Brussels as the country recovers from a $85bn bailout.

Although the post is largely ceremonial, the president has make-or-break power over the country's fragile ruling alliance and the power to dissolve parliament in the event of a crisis.

Since inconclusive elections in October, Portugal's minority Socialist government has been relying on a delicate coalition with the extreme-left to run the country.

READ MORE: Portugal's government ousted by anti-austerity alliance

The overwhelming favourite to win Sunday's vote is law professor and TV pundit Marcelo Rebelo de Sousa.

Known as "Professor Marcelo" to his fans, he comes into the race with a popularity that has been built thanks to decades in the public eye.

The 67-year-old, who made his debut as a political analyst on TV in the early 2000s, is widely expected to break the 50 percent mark for an outright win in Sunday's voting.

A long-time conservative, de Sousa has the backing of right-wing parties but claims total independence.

He insists he will not be partisan but will seek to rule "above the fray".

If none of the 10 candidates breaches this threshold, a runoff will be held on February 14.

Polling booths opened at 0800 GMT and were to close at 1900 GMT, save for the mid-Atlantic Azores archipelago, where they open and close one hour later.

Around 9.7 million people are registered to vote, but the turnout rate in presidential elections is traditionally poor. In 2011, just one voter in two bothered to cast their ballot.

Marcelo Rebelo de Sousa is widely expected to break the 50 percent mark for an outright win [Armando Franca/AP Photo]

Source: AFP