In mid-April 1919, Sir Keith Price, a head of production at the Ministry of Munitions, wrote to the War Office urging the use of new variants of gas against the Bolsheviks in the North Russian theatre. Winston Churchill, then Secretary of State for War and Air, was enthusiastic in his support but was concerned at revealing the new gas in the course of a relatively small campaign. Churchill's concerns having been addressed, massive preparations for the use of the new gas were undertaken. As a trial of the new weapon Kelly, who was now in command of a very mixed outfit on the railway front as part of the Vologda Force, was ordered to carry out a raid on the Bolsheviks under cover of a large ground discharge of gas. Kelly objected less against the gas as against the raid itself whose purposes in his view could be achieved by other methods. The gas raid, due on 17 August 1919, never took place. Kelly was then replaced as commanding officer of his unit and sent back to Britain; the formal reason for his removal was that he had "remarked adversely on matters of military import", criticised his superiors and divulged military secrets in a letter to a friend in England; the contents of the letter constituted a court martial offence.