Congress on Thursday gave final approval to legislation guaranteeing that people who experience sexual harassment at work can seek recourse in the courts, a milestone for the #MeToo movement that prompted a national reckoning on the way sexual misconduct claims are handled.

The measure, which is expected to be signed by Joe Biden, bars employment contracts from forcing people to settle sexual assault or harassment cases through arbitration rather than in court, a process that often benefits employers and keeps misconduct allegations from becoming public.

Significantly, the bill is retroactive, nullifying that language in contracts nationwide and opening the door for people who had been bound by it to take legal action.

Senator Kirsten Gillibrand, who has spearheaded the effort, called it “one of the most significant workplace reforms in American history”.

Gillibrand, a Democrat from New York, said the arbitration process was secretive and biased and denied people a basic constitutional right: a day in court.

“No longer will survivors of sexual assault or harassment in the workplace come forward and be told that they are legally forbidden to sue their employer because somewhere buried in their employment contracts was this forced arbitration clause,” she said.

Gillibrand, who has focused on combating sexual harassment and sexual misconduct in the military, originally introduced the legislation in 2017 with the Republican senator Lindsey Graham.

The legislation had uncommonly broad, bipartisan support in a divided Congress. That allowed the bill to be passed in the Senate by unanimous consent – a procedure almost never used for significant legislation, especially one affecting tens of millions of Americans. The House passed the bill this week on a robust bipartisan basis in a 335- 97 vote.

The former Fox News anchor Gretchen Carlson, who accused the then network chief, Roger Ailes, of making unwanted advances and harming her career when she rejected him, testified in support of the legislation. Some employee contracts at the network included binding arbitration clauses.

Carlson, who appeared with Gillibrand and other senators at a news conference after Senate passage of the bill, said she could never have imagined, after coming forward with her allegations five years ago, that it would lead to a change in the law that both Democrats and Republicans would get behind.

“Marching in the streets can inspire us. Editorials can open our minds. Hashtags can galvanize, but legislation is the only thing that lasts,” Carlson said.

An estimated 60 million American workers have clauses tucked into their employment contracts forcing them to settle any allegations of sexual misconduct in private arbitration proceedings, rather than in court. The widespread practice has come under fire in the wake of the #MeToo movement for forcing employees to seek recourse without a jury, a chance to appeal a decision or the sunlight of a public court process.

The White House released a statement earlier this month in support of the bill.