A total of four companies decided to formally respond to Specification P.27/32, these being the Fairey, Hawker Aircraft, Armstrong Whitworth Aircraft, and Bristol Aeroplane Company. Of the submissions made, the Air Ministry selected Armstrong Whitworth and Fairey to produce prototypes to demonstrate their designs. On 10 March 1936, the first Fairey prototype, "K4303", equipped with a Merlin I engine capable of generating , performed its maiden flight at Hayes, Middlesex. The prototype was promptly transferred to RAF Martlesham Heath, Woodbridge, Suffolk for service trials, during which it attained a maximum speed of 257 MPH and reportedly achieved a performance in advance of any contemporary day bomber.