The PM’s spokesman said the Withdrawal Agreement Bill would expand this power to courts below the Supreme Court.
He added this would ensure judges at lower courts would not be “inadvertently” tied to the rulings “for years to come”.
But others warned the move would cause legal uncertainty.
MPs are set for an initial vote on the withdrawal bill on Friday, after the Conservatives won an 80-seat majority at last week’s general election.
Previous rulings of the European Court of Justice (ECJ) are set to be incorporated into the case law followed by British courts after Brexit.
The provision is contained in a separate EU withdrawal law passed in June last year under the premiership of Theresa May.
Previously, only the Supreme Court and the High Court of Justiciary in Scotland would be allowed to depart from these rulings.