Fifty Democratic Congressmen have written to US President Donald Trump to explain his placement of controversial chief strategist Steve Bannon on the National Security Council despite lacking formal foreign policy experience. <br/><br/>The letter follows the introduction of two Democratic bills, one in the Senate and the other in the House of Representatives, on Wednesday aimed at keeping Bannon off the NSC's core Principals Committee and reinstating the permanent status of the chairman of the Joint Chiefs of Staff and the Director of National Intelligence (DNI).<br/>'<br/>Mr Trump had caused an uproar last weekend when he issued a memorandum that reorganised the NSC to elevate Bannon onto the Principals Committee and to relegate the Joint Chiefs chairman and DNI to roles where they only attend when issues pertaining to their responsibilities and expertise are discussed.<br/><br/>