During early 1988 the Chancellor of the Exchequer, Nigel Lawson, requested officials to study the case for, and practicalities of, giving the Bank of England statutory independence.
The Treasury did not approve the change, but Lawson nonetheless prepared a memorandum for the Prime Minister urging an independent Bank. The initiative came to nothing, because Margaret Thatcher rejected the proposal. But after she left No.10 work continued on Bank of England independence on the initiative of officials, preparing in case ministers asked for a reexamination of the issue. In the event that moment came only with the arrival of the new Labour Government in May 1997.
Records of this were released by the Treasury on 7 March 2005 as an FOI disclosure...
http://www.hm-treasury.gov.uk/about/informatio n/foi_disclosures/foi_indempc_070305.cfm