New Delhi, May 26 -- Federal judges have blocked Alabama from using a Republican-backed congressional map that could have reshaped a key U.S. House race ahead of the midterm elections, dealing a setback to GOP efforts to protect their narrow House majority.

The ruling is the latest chapter in a broader national battle over congressional redistricting, voting rights and political control of the House of Representatives.

A three-judge federal panel issued a preliminary injunction preventing Alabama from switching to a new congressional map supported by Republicans.

The judges ruled that the proposed map "intentionally discriminated based on race" because it included only one Black-majority district in a state where Black residents accoun...