The figure constitutes a whopping 1500 percent increase from the 15 million CFA francs in the 2016 election.
Benin's former leader on Tuesday accused President Patrice Talon of "declaring war" on the nation through the adoption of a new law demanding exorbitant fees from anyone running for election.
Adopted by parliament earlier this month, the legislation demands an eye-watering fee of 250 million CFA francs -- around 380,000 euros or $450,000 -- for candidates hoping to contest the 2020 presidential election.
The figure constitutes a whopping 1500 percent increase from the 15 million CFA francs in the 2016 election in a move denounced by the opposition as favouring the rich and well-connected.
There is an even bigger hike for fielding a candidate list in the legislative elections, with the fee rising from 8.3 million CFA francs to 249 million.
"By brutally and clumsily excluding anyone who is young, poor or disadvantaged, the government and its allies in parliament have this time gone too far," said Nicephore Soglo, who served as president between 1991-1996.
"It is nothing less than a declaration of war," the 83-year-old told reporters at a press conference at his home in Cotonou, Benin's economic capital.
"We are playing with fire," said Soglo, who was Benin's first democratically-elected president after nearly two decades of a Marxist-Leninist regime led by Mathieu Kerekou, a revolutionary who seized power during a military coup.
As honorary president of the opposition party Renaissance Benin, Soglo has never minced his words about Talon's leadership, denouncing it over its authoritarian drift.
Since his election in March 2016, Talon has adopted a series of increasingly controversial reforms, triggering strikes and protests in this tiny West African country.
Earlier this month, protesters hit the streets after parliament adopted a law limiting the right to go on strike to a maximum of 10 days per year, for both public and private sector workers.
And last week, the authorities banned a gathering in Cotonou to protest against a new law imposing a sharp hike in internet costs, which has driven up the price of using social networks from 2 CFA francs to 10 CFA francs per megabyte.
A former French colony with 10.8 million people, Benin is classed as a low-income country by the World Bank, with poor social and economic indicators in areas such as health and education.
With scarce natural resources, it relies on its port business to survive, with Cotonou acting as a key West African distribution hub for imported cars, fabrics, and food from all over the world.