Gérard Guedegbe is a local journalist based in Benin's capital, Cotonou.
Throughout the march the politicians shouted anti-corruption slogans, such as "We demand punishment for the looters of Benin's economy."
Guedegbe says the march demonstrates the president's attachment to good governance and the fight against corruption in Benin.
He says Mr. Yayi has shown his commitment to ending graft by imprisoning ministers who were corrupt under Benin's previous regime.
Mr. Yayi won almost 75 percent of votes in last year's presidential election. His platform promised to rejuvenate Benin's struggling economy, which has suffered from low prices for its main export, cotton, and to fight corruption in the country.
But Antoine Glaser, an African specialist based in Paris, says despite Mr. Yayi's promises corruption is still widespread in Benin and he is skeptical that real change is taking place.
"The new president he talks a lot about it, especially before he arrived at the presidency," he said. "They are speaking more about it than they really act."
He says most corruption is found in the economic sector, which has not been sufficiently targeted.
"In Benin, all the corruption was around the harbor, in between import/export," he said. "People usually do not pay taxes when they import products."
Mr. Yayi's campaign to fight graft has met with some resistance. In March gunmen opened fire on Mr. Yayi's convoy. The president said enemies of his anti-graft policies had organized the apparent assassination attempt.
The anti-corruption organization Transparency International ranked Benin as one of the 50 most corrupt countries in the world.
