The president of Equatorial Guinea is expected to dominate the country's election Sunday, securing a new seven-year term that could take his reign past the four-decade mark.

The 73-year-old Teodoro Obiang seized power after a military coup in 1979 and is already Africa's longest-serving leader and the world's longest-serving non-royal head of state.

Rights groups and critics accuse him of overseeing a deeply corrupt government that represses and tortures opponents.

There appear to be six opponents competing against Obiang although several are political unknowns.

Tutu Alicante, a leading government critic, says they could be pawns used by the government to create the illusion of a contest.

There is widespread speculation Obiang wants his son Teodorin to succeed him.

The government has promised a "successful" vote with "maximum transparency."