Sky News quoted governmental sources Monday as saying British Foreign Minister Jack Straw warned U.S. Secretary of State Colin Powell of Britain's "strong reservations" about the military commission trials and said Britain expects the United States to meet international standards of fairness.
The trials involve Feroz Abbasi and Moazzam Begg.
Foreign Office minister Chris Mullin warned if the issue arises, Britain would make clear its "fundamental opposition" to the use of the death penalty in all circumstances.
Abbasi, a computer student from south London, and Begg, from Birmingham, were among the first six people put forward for military trial by the United States last week. Although both men have been in custody for more than a year, neither has yet been charged with any crimes.