Democrats in Congress are set to introduce a bill on Thursday to increase the number of Supreme Court justices by four.
The proposal seeks to break Conservative control of the court, but is expected to generate fierce Republican opposition.
Senator Ed Markey and Rep. Jerold Nadler, Hank Johnson and Mondeir Jones are scheduled to hold a press conference on Thursday to announce the bill in both houses.
The initiative calls for an increase in the number of judges from the current nine to 13, according to a copy of the Senate bill that Reuters has obtained.
President Joe Biden announced last Friday the formation of a bipartisan commission to examine possible changes to the Supreme Court, including expanding or limiting the terms of office of judges in lieu of current life appointments.
The number of Supreme Court justices has been nine since 1869, but Congress has the power to change it, and this has happened several times before.