Central Policy Review Staff
The Central Policy Review Staff (CPRS), nicknamed the "Think-Tank", was an independent unit within the Cabinet Office of the United Kingdom tasked with developing long term strategy and co-ordinating policy across government departments. It was established by Edward Heath in February 1971 but was later disbanded by Margaret Thatcher following the 1983 general election.
Source: Wikipedia — Central Policy Review Staff (CC BY-SA 4.0)