KIEV, Ukraine - Hundreds of demonstrators marched across the Ukrainian capital Thursday calling for the impeachment of the country’s president over embezzlement claims.

President Petro Poroshenko, who is seeking re-election in a March 31 vote, has come under fire over a media investigation that implicated one of his senior associates in the alleged embezzlement of military funds.

The report has dealt another blow to Poroshenko, whose popularity has sunk because of rampant official corruption and economic woes that followed Russia’s 2014 annexation of Ukraine’s Crimean Peninsula. Poroshenko’s rival in the race, former Prime Minister Yulia Tymoshenko, has jumped at the allegations to push for Poroshenko’s impeachment.

Protesters carried banners that read, “Candidates are many but there is only one marauder,” mimicking Poroshenko’s campaign slogan, “Candidates are many but there is only one president.”

Polls show that Poroshenko and Tymoshenko are both trailing comedian Volodymyr Zelenskiy, who plays the nation’s president in a hugely popular TV series.

Zelenskiy also mocked Poroshenko’s slogan, saying on Facebook, “Candidates are many but one of them will certainly go to jail.”

The investigation, conducted by investigative reporters at Bihus.info, claimed that the embezzlement scheme involved state-controlled defence plants, and cost the state 250 million hryvnias (about $9 million.) The scheme allegedly involved a factory that was controlled by Poroshenko.

Poroshenko has denied involvement in the embezzlement and ordered prosecutors to investigate. The parliament on Thursday set up its own a panel to look into the allegations.

On Wednesday, the country was also rocked by the constitutional Court’s decision to annul a legal article requiring officials to prove that their assets have legitimate origins. The court ruled that the article violated the presumption-of-innocence principle.

Ukraine adopted the legal provision in 2015 under pressure from the International Monetary Fund and the European Union, which made their financial assistance to Ukraine contingent on stronger anti-corruption efforts.

Valdis Dombrovskis, a European Commission vice-president, expressed concern about the move during Thursday’s visit to Kyiv.

“We must see what exactly the concerns of constitutional Court were, and how it will affect the effectiveness of fight against corruption,” he said.

Zelenskiy harshly criticized the constitutional Court’s decision, saying that “the outgoing government has decided to get away with what it has stolen from the people and the army.”