President Joe Biden and Vice President Kamala Harris’ efforts to sell their green agenda and infrastructure plan are being complicated by a thorny conflict of interest for Energy Secretary Jennifer Granholm — who stands to gain a windfall from stock options in a private electric vehicle company.

Last month, Biden took a virtual tour of Proterra, a company Granholm holds millions of dollars in vested stock options in and previously sat on the board of. During the tour Biden praised employees and the CEO for their work in the electric vehicle space.