530 Mr John Curtin, Prime Minister, to Mr Clement Attlee, U.K. Secretary of State for Dominion Affairs
Cablegram 347 CANBERRA, 25 June 1942
MOST IMMEDIATE MOST SECRET
I have received your cablegram of 24th June  through the High Commissioner of the United Kingdom. 
2. The Commonwealth Government realizes and shares your anxieties regarding the position in the Middle East. Our agreement that the 9th Division A.I.F. should remain there until it could be relieved was a manifestation of our vital interest in the security of this region, notwithstanding the great need for this division in Australia.
3. Your communication has caused me surprise and concern because the special plan for air support of Australia under which a wing of three Spitfire squadrons would be shipped to Australia in June was made at the instance of Mr Churchill between him and the special representative of the Commonwealth Government, Dr. Evatt , while he was in London. Please see Major-General Ismay's letter of 28th May. 
4. As mentioned to the Prime Minister in Johcu No.33 , it was stated that this practical manifestation of support would do much to encourage the Australian people, it would make a great contribution to the security of the Commonwealth and would have a demoralizing effect on the Japanese Air Force. Japanese fighter aircraft have displayed superiority in their ability to operate at higher altitudes and in their manoeuvreability. 5. The action in the Coral Sea was a temporary deliverance of the Commonwealth from the immediate threat of invasion. The enemy still possesses great strength and has the initiative. He also still has his bases in the nearby islands to the north of Australia. It may therefore be only a temporary lull in offensive operations in the Southwest Pacific Area. The Commander-in-Chief  has consistently and strongly represented to the Commonwealth Government the need for all possible measures to strengthen the defence of Australia, particularly in the air, while time and opportunity permit.
6. The number of serviceable aircraft in Australia at present is below initial establishment of the R.A.A.F. and the United States Air Corps. The additional aspects of initial reserve and wastage make the picture worse. The provision of the Spitfires is a necessary reinforcement in strength which will have a stimulating effect on the morale of our own Air Force.
7. It is stated that if the Spitfires were diverted they would arrive in the Middle East about 25th July. If the situation is desperate it would not appear that either from the aspects of time or numbers they would swing the balance in our favour. On the other hand they may make all the difference in the defence of Australia, which is far more remote from the sources of supply.
8. In view of the foregoing, the Commonwealth Government cannot consent to the proposed diversion of the 42 aircraft and it requests that other arrangements be made for the reinforcement of the Middle East. It is to be noted that it is a fortuitous circumstance that these aircraft are at sea en route to Australia and, were it otherwise, reinforcement by other means would be necessary.