Senegalese voters are choosing on Sunday whether to give President Macky Sall a second term in office as critics accused the incumbent leader of having blocked the strongest opposition candidates from running against him.

Sall has dubbed himself "the builder of modern Senegal," and billboards lining Dakar's highways tout the 221 kilometres of new roads and high speed train in the works that will link the capital to its brand new international airport.

The West African country's annual GDP growth was 7.2 percent in 2017, and Senegal has long been a bastion of democracy in a region long plagued by coups and power grabs. However, Sall's opponents have accused him of jailing his adversaries for political gain ahead of his re-election bid.

In Dakar's Guediawaye neighbourhood, voters made their way across a sand courtyard to vote at the Kawsara Fall school just before 08:00, many clutching prayer beads and plastic cups of coffee.

Mamadou Tall, 45, said that he was backing main opposition candidate Idrissa Seck because the president's big projects had yet to improve the lives of most Senegalese.

"Around here there are many young men taking the boats to Europe. Unemployment is a real problem," said Tall, who wore a long flowing white embroidered robe known as a boubou. "In many families there is one person working and he's supporting 12 to 15 relatives."

While the president has touted the city's new airport and the high-speed train that will eventually connect it to Dakar, Tall said the project began under his predecessor, Abdoulaye Wade.

"Most people here in this neighbourhood will never get on a plane," he said.

Tangible benefits 

Others, though, pointed to tangible benefits over the last seven years. Mariama Diouf, 39, said her living room used to flood every rainy season. She no longer has to wade through the streets of her neighbourhood on her way to sell goods at the market.

"Where I live, Macky has improved things," Diouf said. "Even if you're not a Macky supporter you have to admit he has made things better."

Sall became president in 2012 after beating longtime former President Abdoulaye Wade. A constitutional referendum shortened the presidential term to five years from seven since then.

Absent from Sunday's ballot were two prominent opposition figures who had sought to run but were blocked from doing so after both were convicted of corruption charges. Supporters for both men maintain the charges were politically motivated and part of an effort to sideline their candidacies.

Former Dakar Mayor Khalifa Sall is currently serving a five-year sentence on charges of misusing public funds. Karim Wade, son of the former president, has been in self-imposed exile in Qatar since he was released from prison after serving time on corruption charges.