Brazil President Jair Bolsonaro’s popularity fell to the lowest level since assuming office as he's accused of turning a blind eye to an alleged kickback scheme in the purchase of coronavirus vaccines.

Bolsonaro is approved by 34% of the population, down from 44% in February, according to an MDA poll published on Monday by the National Transport Confederation. Meanwhile, rejection rates for the president and his government hit all-time highs of 63% and 48%, respectively.

Roughly 40% said they would prefer former President Luiz Inacio Lula da Silva to win next year’s election, compared to 25% who want Bolsonaro as head of state for another term. About 30% would like to see someone who’s not the former president nor the incumbent winning.

Bolsonaro, whose popularity was already suffering amid a slow vaccination campaign and more than half a million deaths from Covid, came under additional pressure last week when a Supreme Court justice authorized a probe into the president’s possible negligence in the handling of allegations of corruption in vaccine purchases. His former environment minister also quit last month amid a police investigation into timber exports. Complicating the president’s standing further, surging inflation is hurting the nation’s poor.

The MDA poll interviewed 2,002 people nationwide and has a margin of error of plus or minus 2.2 percentage points.