HSA's chief aircraft designer Sir Sydney Camm decided that the company should investigate the prospects of developing and manufacturing a viable combat-capable vertical take-off and landing (VTOL) fighter aircraft. Along with the subsonic Hawker P.1121 fighter (which would become the Hawker Siddeley Harrier later on, a supersonic design, designated as the "P.1150" was produced; however, the release of NBMR-3, and subsequent revisions to it, led to the P.1150 proposal being considered to be undersized and thus unsatisfactory, which led to a desire for a redesign. The new, larger aircraft design soon emerged, which was initially designated as "P.1150/3" prior to being redesignated as the "P.1154". In January 1962, HSA submitted the P.1154 design to NATO via the Ministry of Aviation. NBMR.3 attracted a total of eleven contenders, including Dassault's Mirage IIIV proposal, which would become viewed as the principal competitor to the P.1154. Substantial support for the Mirage IIIV came from Britain, work on the programme having involved the British Aircraft Corporation (BAC), while the Dassault-led design also held the favour of several members of the British Air Staff. While the P.1154 was judged to be technically superior, the Mirage IIIV had acquired a greater level of political palatability due to the co-operative development and production aspects proposed for the programme, under which work was to be distributed across a number of member nations. Protracting political maneuvering by firms and national governments alike was deployed in attempts to secure their respective project's selection. In May 1962, the P.1154 emerged as the winner in the competition for the NBMR.3 over the Mirage IIIV. While the Mirage IIIV had not been selected to meet NBMR-3, however this did not lead to orders for the rival P.1154 being placed. The French government subsequently withdrew from participation once the Dassault design had not emerged victorious. According to aviation author Jeffort, the Mirage IIIV had been rejected mainly because of its excessive complexity, using nine engines compared to the P.1154's single-engine approach. However, NATO lacked any central budget, instead relying on individual member nations to actually procure military equipment, while the NBMR-3 selection went unheeded by all of the NATO member nations. Thus, in 1965, the whole NATO project was unceremoniously terminated.