Voters in Gabon go to the polls on Sunday to elect a successor to President Omar Bongo, who died in June after leading his country for 41 years. Favourite to succeed him is his son, Ali Ben Bongo, 50, candidate of the ruling Gabonese Democratic Party (PDG). He has promised to boost what he says is the prosperity that Gabon enjoyed during his father's years in power. Mr Bongo's rivals include former government ministers Andre Mba Obame and Casimir Oye Mba. They have denounced what they say is endemic corruption and favouritism in Gabon. On Friday at least five out of 23 opposition candidates announced they were pulling out of the race and pledged their support for Mr Obame. Wealthy leader Omar Bongo was one of the world's richest men, with a string of properties in France. He was an unflinching ally of France and a key element in French influence in Central Africa. BBC Africa analyst Martin Plaut says that Ali Ben Bongo is seen as less closely linked to the French elite than his father, despite being educated at the Sorbonne. He is also somewhat detached from ordinary Gabonese, struggling to speak local languages with real fluency, our correspondent says. Gabon is sub-Saharan Africa's fourth biggest oil producer and Africa's second biggest wood exporter, although most of its 1.4 million people live in poverty. Voting, which is due to begin at 0700 (0600 GMT), will be monitored by observers from organisations including the African Union. Polls will close at 1800 (1700 GMT). Source: BBC