Investor unrest is increasing after Bayer sweetened Chief Executive Officer Werner Baumann’s bonus even as court battles over Monsanto’s Roundup weedkiller have destroyed billions in the company’s market value.

Shareholder and corporate governance expert Christian Strenger, a former CEO of DWS Investment, filed a motion on Thursday proposing that members of the supervisory board not be discharged of responsibility for their actions last year. Backing from fellow investors would amount to a vote of no confidence for the board, which approved a 28 percent increase in Baumann’s bonus and has stood behind him even as Roundup lawsuits piled up.

Pressure is rising on Baumann, who will face Bayer investors April 26 at the company’s annual meeting. The legal fight over whether Roundup causes cancer has wiped nearly 35 billion euros ($40 billion) off Bayer’s market value since it acquired Creve Coeur-based Monsanto last June. The CEO is facing challenges outside the courtroom too, as he seeks to slice away about a 10th of Bayer’s global workforce and reshape the business after his agrochemicals megadeal.