Republicans in the US Congress have called on President Obama to explain the legality of America's military involvements in Libya. The Speaker of the House of Representatives has warned in a letter that the Obama administration risks breaking a law which limits the President's powers. The Speaker John Boehner's letter refers to the war powers of 1973 which gives US President 60 days to secure congressional approval for military action and a further 30 days is allowed for the withdrawal of troops. Regarding Libya Mr. Boehner points out that the total of 90 days will be reached on Sunday. He calls on Barak Obama to explain by Friday his legal justification for action in the absence of congressional action. In practice many Republicans have supported the NATO intervention in Libya.