Two leading Senate Democrats introduced a bill Thursday that would strictly limit the use of arbitration, a process used to resolve legal disputes that is often stacked against consumers.

The bill, introduced by Senator Patrick J. Leahy, Democrat of Vermont, and co-sponsored by Senator Al Franken, Democrat of Minnesota, would prevent civil rights cases, employment disputes and other crucial lawsuits from being forced into arbitration, where judges and juries have been replaced by arbitrators who commonly consider the companies their clients.

“Legal fine print tips the scales against us,” Mr. Leahy said. “It is forcing consumers into private arbitration, denying us of our constitutional right to protect ourselves in court.” Regulators and lawmakers have been pushing to prevent companies, large and small, from inserting arbitration clauses in contracts. It is virtually impossible to rent a car, open a bank account, get a job or enroll an elderly parent in a nursing home without signing away the right to take a case to court.

Embedded in tens of millions of contracts, the clauses prevent Americans from joining in class-action lawsuits, the only realistic way that an individual can do battle with a wealthy corporation.

The prevalence of arbitration clauses was the subject of a series of articles in The New York Times last year. Since then, efforts to rein in the practice have gained momentum, giving rise to several legislative proposals and calls on the Obama administration to use executive authority to bar federal contractors from using arbitration.

In its investigation, based on thousands of court records and interviews with hundreds of lawyers, judges and arbitrators in 35 states, The Times found that by using arbitration clauses corporations can circumvent the courts and quash challenges to discrimination, predatory lending and even wrongful death.