As recently as late June 1941, it seems that General Blamey had not yet decided to request that the 9th Australian Division be withdrawn from Tobruk. There were several things that would cause him to decide, however. For one thing, the Germans seemed to be at the point of overrunning Russia. The British intelligence perspective was that Russia was being totally dominated and might collapse at any moment. Other factors were that the senior medical advisor and General Morshead agreed that the physical condition of the Australian soldiers in Tobruk was rapidly declining. Another factor was that the campaign in Syria against the Vichy French was ending. An armistice was declared on 12 July. That would make easier pulling the Australian divisions into one organization.
July 1941 seemed like a good opportunity to remove the 9th Australian Division from Tobruk. The natural thing was for General Blamey to write to General Aunchinleck requesting that the 9th Australian Division be relieved from the defense of Tobruk. The excuse given was that the condition of the Australian soldiers had declined and that they had taken heavy losses in the fighting to defend Tobruk. The second excuse given was that the Australian government had always wanted the Australian divisions to be part of a single organization. When they looked at the three Australian divisions, the 6th had been heavliy engaged in Libya, then Greece, and finally, in the defense of Crete. The division had taken heavy losses. The 7th had just completed the conquest of Vichy Syria and had also taken losses in the process. They were also short of the 18th Brigade which was presently in Tobruk. The 9th had been in continuous combat since March 1941 and had also taken heavy losses in the process.
General Blamey communicated with the Australian prime minister and provided him a copy of the letter to General Auchinleck. General Blamey wanted to see the Australian divisions assembled in Palestine so that they could form an Australian organization. He saw the main obstacle the reluctance of the British to allow it to happen. This is base on the account in Vol.III of the Australian Official History.