Polling stations opened across Uruguay on Sunday with the country's first leftist president favored to reclaim the post in a run-off election.

With heavy rain forecast for much of the country, voting began at 8:00 am (1000 GMT) to elect a successor to rabble-rousing President Jose Mujica.

Mujica is looking to hand power back to his predecessor, Tabare Vazquez, a 74-year-old cancer doctor who kept up his practice even while head of state from 2005 to 2010. Voter surveys suggested Vazquez would see off center-right challenger Luis Lacalle Pou, 41, a former president's son and lawyer.

The polls close at 7:30 pm (2130 GMT) and casting a ballot is compulsory for Uruguay's 2.6 million voters.