In August 1941, the Commander-in-Chief (CinC) of Far East Command Air Chief Marshal Robert Brooke-Popham submitted a plan with the code-name Matador, to London for approval (PRO record FO 371/28163).

The plan relied on the assumption that the Japanese would land on the east coast of Siam at Songkhla and Pattani, then advance south to Jitra and Kroh.

On 5 December, London gave permission for the C-in-C Far East Command to decide if Operation Matador should begin.

That evening, in a meeting with the Governor, Sir Shenton Thomas, and Brooke-Popham, the General Officer Commanding Malaya Arthur Percival recommended that a forestalling attack was premature.

They would use the Bangkok airport and the airfields of Southern Siam to establish air superiority and then invade from the Kra Isthmus.