A bipartisan group of U.S. lawmakers unveiled legislation on Wednesday that would overhaul aspects of the National Security Agency's warrantless internet surveillance program in an effort to install additional privacy protections.

The bill, which was to be formally introduced as soon as Thursday, is likely to revive debate in Washington over the balance between security and privacy, amid concerns among some lawmakers in both parties that the government may be too eager to spy on its own citizens.

The legislation, written by the House of Representatives Judiciary Committee, is seen by civil liberties groups as the best chance for Congress to reform the relevant law, known as Section 702 of the Foreign Intelligence Surveillance Act, before its expiration on Dec. 31.