Conservatives are among MPs battling to stop the government granting immunity to British ministers, spies and military personnel for involvement in murder and torture abroad.
Tory grandee David Davis is bringing a series of amendments to the National Security Bill, which has alarmed human rights groups and anti-war crime campaigners.
The proposed changes, aiming to strip out clauses granting legal immunity and restricting damages for torture survivors, will be debated in the House of Commons later on Wednesday.