Meanwhile, the Gallipoli Campaign had ended and the AIF in Egypt was in the process of doubling in size from two divisions to four. Birdwood wished to appoint two British generals to command the new divisions, but Senator Pearce opposed this, ordering that one be given to McCay. On 22 March 1916, McCay arrived back in Egypt to assume command of the 5th Division. He found that General Headquarters, Egyptian Expeditionary Force had ordered II Anzac Corps, of which the 5th Division was a part, to replace I Anzac Corps in the defence of the Suez Canal. Owing to a shortage of rolling stock, the 4th and 5th Divisions were ordered to undertake a three-day route march across the desert under service conditions, carrying their packs and weapons. This proved to be a greater test of staff and troops than anticipated, and many men dropped from thirst or exhaustion. Many of his men blamed McCay for subjecting them to such a humiliating and severe trial.