In December 1962, the then Prime Minister of Great Britain, Mr. Harold Macmillan, met with John F. Kennedy, then President of the United States, at Nassau in the Bahama Islands. They discussed the cancellation of the Skybolt project. Skybolt was a U.S. development project which the U.S. had agreed to share with the U.K. It had been planned as U.K.'s prime deterrent and its cancellation caused the U.K. some concern. At this Nassau meeting, it was agreed that the POLARIS A3P would be made available to Britain in order to maintain the U.K.'s deterrent potential during the years ahead. This agreement became known as the "Nassau Agreement." It eventually resulted in signing of the "U.S./U.K. POLARIS Sales Agreement" in April 1963. It was further agreed that Britain would build its own submarines of their own design, including the nuclear propulsion plant, but would be armed with the POLARIS A3P missile. Britain would also design and construct its own nuclear warheads for the POLARIS missiles.
A British Admiralty negotiating team came to the U.S. to negotiate a detailed U.S./U.K. agreement. The POLARIS Sales Agreement was signed on 6 April 1963. Upon approval of this agreement, work began in earnest and continued at an intense pace ever since. VADM R. N. MacKenzie was named the U.K. Chief POLARIS Executive (CPE) and he was authorized to use personnel from the MOD(N) for the production of submarines, ground support, and mechanical and electrical equipment. The Ministry of Public Buildings and Works has prime responsibility for providing facilities ashore for supporting and maintaining the entire system. The Ministry of Aviation has the responsibility, within the U.K., for procurement of the POLARIS missile, including the reentry system and all necessary associated support equipment. It also acts as the U.K. approving authority for the reentry system's warhead. Through the U.K. Atomic Energy Authority, design responsibility for the U.K. warhead is in the Aldermaston Atomic Weapons Research Establishment (AWRE), under the direction of the Ministry of Aviation.
To ensure cooperation and coordination, a Joint U.S.-U.K. Steering Task Group and a Joint U.S.-U.K. Reentry System Working Group were formed. These were parallel structure groups to those in the U.S. FBM Program.
Contracts were released to British industry for various parts of their weapon system. Among them were:
a. Vickers Ltd. (shipbuilder) for the launching system
b. BAC for the POLARIS missile, test equipment, ULCER
c. GECfor fire control and test instrumentation subsystem
d. Elliott & Sperryfor the navigation system
e. EMIfor the weapon control subsystem simulator
f. Vickers, Barrow & Cammell Laird, Burkenhead shipbuilder for the submarines.