With decolonisation sweeping the colonial world, and Britain no longer willing (or able) to bear the financial burdens of the Empire, the colonial authorities sought to prepare the Solomons for self-governance. Appointed Executive and Legislative Councils were established in 1960, with a degree of elected Solomon Islander representation introduced in 1964 and then extended in 1967. A new constitution was drawn up in 1970 which merged the two Councils into one Governing Council, though the British Governor still retained extensive powers. Discontent with this prompted the creation of a new constitution in 1974 which reduced much of the Governor's remaining powers and created the post of Chief Minister, first held by Solomon Mamaloni. Full self-government for the territory was achieved in 1976, a year after the independence of neighbouring Papua New Guinea from Australia. Meanwhile, discontent grew in the Western islands, with many fearing marginalisation in future a Honiara- or Malaita-dominated state, prompting the formation of the Western Breakaway Movement. A conference held in London in 1977 agreed that the Solomons would gain full independence the following year. Under the terms of the Solomon Islands Act 1978 the country was annexed to Her Majesty's dominions and granted independence on 7 July 1978. The first Prime Minister was Sir Peter Kenilorea of the Solomon Islands United Party (SIUP), with Queen Elizabeth II becoming Queen of Solomon Islands, represented locally by a Governor General.