Sen. Bernie Sanders exits the stage after speaking during The Iowa Democratic Party Liberty & Justice Celebration on November 1, 2019, in Des Moines, Iowa. JOSHUA LOTT / GETTY IMAGES

Senate Budget Chairman Bernie Sanders (I-Vermont) has called on top oil and gas executives to testify at a hearing on “The Cost of Inaction on Climate Change” before the budget committee next Thursday.

The senator invited BP America President David C. Lawler, Chevron CEO Michael Wirth and ExxonMobil CEO Darren W. Woods to testify. Sanders told CBS that Lawler has already denied the request sent on Tuesday. “These guys don’t want to answer hard questions,” Sanders said. BP, Chevron and ExxonMobil are some of the biggest carbon emitters in the world.

Sanders told CBS that the distortion of climate research by the oil and gas majors over the past decades is “one of the scandals of our lifetime.” Research and reporting have found that companies like Exxon have participated in a decades-long disinformation campaign in order to sow doubt over whether or not fossil fuels cause global warming and climate change.