the diverging requirements of the RAF and Royal Navy, the aircraft's development had started to stumble. As a result of modifications towards meeting the naval requirements having been performed, by July 1963, weight gain had become a considerable issue for the aircraft. By that point, the Royal Navy was expressly criticising the choice of a V/STOL aircraft. By August 1963, HSA was openly expressing the view that the range of changes being made to the aircraft was damaging its potential for export sales. At the same time, the Navy stated that it regarded the P.1154 to be a second-rate interceptor, and the RAF openly decried the loss of strike performance. By October 1963, the Ministry of Aviation was concerned with the project's progress, and noted that the effort to combine a strike aircraft and a fighter in a single aircraft, and trying to fit that same airframe to both of the services, was "unsound". By October 1963, according to Wood, the situation had become critical and some officials were beginning to examine alternative options, such as conventional fighter aircraft in the form of the McDonnell Douglas F-4 Phantom II. By November 1963, the RAF reportedly still found the P.1154 to be a suitable platform, while the Royal Navy appeared to be considering the F-4 Phantom II as being a better fit for its needs. In response, HSA elected to focus its efforts on the RAF version. In late 1963, dissatisfied with the progress of the 'bi-service' model, the government examined three alternative options for the programme: to proceed with an RAF-orientated P.1154 while the Naval version would be delayed, pursue the development of a full dual-service P.1154 model with only limited differences between the services, or the complete termination of the program with the service's requirements to be re-appraised. In November 1963, the Sunday Telegraph publicly announced that the bi-service P.1154 had been aborted. Wood attributes Thorneycroft's ambition to reconcile the requirements of the two services into the one model and insistence on this vision as having "put the whole project in jeopardy". Around this point, the Royal Navy expressed their open preference for the F-4 Phantom II and soon Thorneycroft conceded that the service would get this aircraft instead, and that development of the P.1154 would continue to meet the RAF's requirement. On 26 February 1964, it was announced in the House of Commons by the Conservative government that