While the Eighth Army was still engaged in the Tunisian campaign, planning was in train in Algiers and Cairo for Operation Husky, the Allied invasion of Sicily. Unable to devote much time to it but concerned at how it was progressing, Montgomery decided that de Guingand would go to Cairo as his deputy, in charge of the planning group known as Force 545. In view of his new status and increased responsibility, de Guingand was granted the local rank major-general. He arrived in Cairo on 15 April. On taking over the planning for Operation Husky, he became concerned that it called for a series of dispersed landings based on the assumption that the German and Italian forces would not mount a fierce resistance. This ran contrary to the Eighth Army's experience with them in the North African campaign. Montgomery listened to de Guingand's appreciation on 23 April, and then sent a message to the Supreme Allied Commander, General Dwight D. Eisenhower in Algiers, urging that the invasion plan be changed to concentrate the landings.