Democratic presidential candidate and U.S. Sen. Bernie Sanders (I-VT) speaks during the 2020 Public Service Forum hosted by the American Federation of State, County and Municipal Employees (AFSCME) at UNLV on August 3, 2019 in Las Vegas, Nevada.

Democratic presidential contender Bernie Sanders released a plan Wednesday that aims to dramatically increase U.S. labor union membership.

The Vermont independent's sweeping proposal would make it easier for workers to join unions, end the so-called right-to-work laws recently favored by Republicans and bar the replacement of striking workers, his campaign said Wednesday. It would also stop federal contracts to companies that pay workers less than $15 per hour, outsource jobs or discourage workers from forming unions, among other measures.

Through the plan, Sanders would aim to double union membership by the end of his first term in office in January 2025. He contends it would boost pay and benefits for U.S. workers who have seen money disproportionately flow to companies and their executives.

Sanders' measure comes as the more than 20 Democratic presidential candidates fight for support from politically influential labor unions. He released it ahead of a speech later Wednesday at an AFL-CIO event in Iowa, which will hold the first Democratic presidential nominating contest in February.