(CNN) With Congress eying to exit Washington in a few weeks, Sen. Chuck Grassley, the chairman of the influential Judiciary committee, dismissed Senate Majority Leader Mitch McConnell's claim that a major criminal justice reform bill doesn't have the support of the majority of Republicans in the Senate.

At an event Tuesday moderated by The Washington Post, the Iowa Republican said that the bill could pass in three or four days, and would lose Republican support if it gets punted to 2019, when Democrats take control of the House.

"If McConnell will bring this up, it will pass overwhelmingly," Grassley said.

Grassley helped write the legislation, known as the First Step Act, which would allow thousands of current and future federal inmates get out earlier, and rehabilitate back into society through halfway houses, home confinement or other supervision, by reducing drug-related mandatory sentences and making more offenders eligible for early release through earning credits awarded by completing certain activities and programs.

McConnell, the Senate Republican leader, has not said publicly whether he supports or opposes the bill. When asked by CNN Tuesday whether he would put the bill on the floor this year, McConnell said "we're still talking."

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