An observer group from the UK Conservative Party did regard the April 1979 elections as fair , and Margaret Thatcher , the Conservative leader , was personally disposed to recognise Muzorewa 's government and lift sanctions . The potential significance of the Conservative victory in the May 1979 British general election was not lost on Smith , who wrote to Thatcher : " All Rhodesians thank God for your magnificent victory . " The US Senate passed a resolution urging President Carter to remove sanctions and declare Zimbabwe Rhodesia legitimate , but Carter and his Cabinet remained strongly opposed . Carter and Thatcher ultimately decided against accepting Zimbabwe Rhodesia , noting the continued international support for the guerrillas . After the Commonwealth Heads of Government Meeting in Lusaka in August 1979 , the UK Foreign Secretary Lord Carrington invited the Zimbabwe Rhodesian government and the Patriotic Front to attend an all-party constitutional conference at Lancaster House in London , starting on 10 September
Commonwealth Heads of Government Meeting
Commonwealth Heads of Government Meeting 1979
Ian Smith