The Canberra was a foreign aircraft, which meant its superiority in terms of performance did not guarantee political support in spite of the urgent need, particularly in light of there being several rival indigenous aircraft designs. There were also doubts about production availability with English Electric being able to mesh with USAF demands, as well as questions over continued spares support. In March 1951, many of these questions were answered; with production lines already at full capacity meeting Royal Air Force orders and those emerging from other export customers, English Electric entered into discussions with Glenn L. Martin Company. It was proposed that Martin would receive a license to domestically build the Canberra in the United States. According to Gunston and Gilchrist, the Americanization of the Canberra program proved effective at dismissing much of the political opposition to the project.