By the end of 1942, a mock-up of the D.H. 103 had been completed at de Havilland's Hatfield facility and was soon afterwards demonstrated to officials of the Ministry of Aircraft Production. Due to the war, the ministry did not immediately issue permission to construct the D.H. 103. In June 1943, the project stopped being a private venture when the Ministry released Specification F.12/43, which had been written around the D.H. 103 proposal; soon after, the D.H. 103 project received the name Hornet.