Rep. Ro Khanna (D-Calif.) called for Sen. Dianne Feinstein (D-Calif.) to resign “gracefully” Thursday after the Senate voted to undo a Biden administration rule on truck emissions without her present.

“Because Senator Feinstein was absent, the Senate overturned a Biden rule that would cut pollution from heavy duty trucks and causes harm to people’s lungs. We are putting decorum over democracy and our values. It’s time for Senator Feinstein to step down gracefully,” Khanna tweeted Thursday.

The measure passed 50-49 Wednesday, with Sen. Joe Manchin (D-W.Va.) joining every Republican. The rule in question is aimed at cutting emissions from heavy-duty trucks in the form of nitrogen oxides, pollutants that contribute to asthma and acid rain.

Republicans and Manchin called the rule overly burdensome and a potential contributor to inflation.

“When our country faces record-high inflation and vulnerable supply chains, we cannot let the EPA continue to seize unrestrained power and create regulations that devastate our economy,” Manchin said in a statement.

The White House has pledged to veto the measure, and the one-vote margin suggests the Senate lacks the two-thirds majority to override Biden’s veto.

It’s the latest Republican attempt to undo a Biden environmental policy through the Congressional Review Act, which allows a simple majority to undo an executive branch rule. Manchin has supported several such efforts, including an upcoming resolution to restore suspended tariffs on solar energy.

Feinstein, who is retiring in 2024, has been absent since for almost two months — since announcing a shingles diagnosis — from both floor votes and the Senate Judiciary Committee, hindering the confirmation of judges. Earlier this month, the California Democrat offered to cede her position on the panel to another Democrat, but Senate Republicans blocked the assignment.

Khanna earlier this month became the first Democratic lawmaker to call for the 89-year-old Senate stalwart to step down.