Shackleton stood unsuccessfully for Labour at
Epsom in the
1945 general election and in the
1945 Bournemouth by-election. In 1946, he was elected for Labour as Member of Parliament for
Preston in a by-election. In 1949 he was appointed as
Parliamentary Private Secretary (PPS) to the
Minister of Supply,
George Strauss. A boundary change divided Preston into two seats, and in 1950 Shackleton was elected as MP for
Preston South on a much-reduced majority. In the following year he was promoted to be PPS to
Lord President of the Council and
Foreign Secretary Herbert Morrison, one of the heavyweight political figures in the post-war government. He was re-elected in 1951. At the 1955 election, he was defeated. Hugh Gaitskell recommended Shackleton to the Prime Minister, and on 11 August 1958 he was created a
life peer by
letters patent as
Baron Shackleton, of
Burley in the
County of Southampton. Shackleton delivered his maiden speech in the
House of Lords on 11 November 1958, in a debate on a Wages Councils bill, one he thoroughly approved of and welcomed, to increase understanding between unions and management. In
Harold Wilson's government, he served as
Minister of Defence for the
RAF from 1964 to 1967. He was sworn of the Privy Council in 1966 and made Deputy Leader of the House of Lords a year later. As
Minister without Portfolio in 1967–1968 and
Paymaster General in 1968, he had a seat in the Cabinet. During the
Aden Emergency he was sent on a Special Mission as British Resident to help with the British withdrawal. In April 1968, after the budget, Wilson made Shackleton Leader of the
House of Lords, succeeding the
Earl of Longford. Shackleton was active in Wilson's proposals for
House of Lords reform, designed to reduce the delaying powers of the Lords from two years to just six months, and he liaised between committees and sub-committees, but in April 1969 Wilson dropped the bill to "concentrate on priorities". Sitting on the committee for Civil Service Reform, Shackleton successfully widened access to entry for scientists. Shackleton remained Leader of the House of Lords until a Conservative government was elected in 1970 and thereafter was Opposition Leader in the Lords. From 1971, Shackleton was President of the
Royal Geographical Society. Lord Shackleton was appointed a
Knight Companion of the Order of the Garter in 1974. From 1976 until 1992 he was Chairman of the joint-Political Honours and Scrutiny Committee. Lord Shackleton's report, commissioned by
James Callaghan, described the economic future of the Falkland Islands, the value of the being British to the islanders, and how their lot could be improved. It included the invaluable role eventually played by
HMS Endurance. Between 1988 and 1989 he chaired the Lords Science and Technology Committee and in 1989 was elected a
Fellow of the Royal Society under Statute 12, effectively an honorary fellow. He also served as Chairman of the East European Trade Council In 1990 Shackleton was appointed an honorary Companion of the
Order of Australia (AC), Australia's highest civilian honour, "for service to Australian/British relations, particularly through the
Britain–Australia Society. Lord Shackleton was Pro-Chancellor of the
University of Southampton, in which role he was deeply interested in the development of
geography at Southampton. A portrait photograph of Lord Shackleton was unveiled by his daughter Alexandra Shackleton in December 1997 in the university's Shackleton Building, which houses the Departments of Geography and Psychology. In 1994 he became the Life President of the newly founded James Caird Society, named after the boat in which his explorer father and crew escaped Antarctica (itself, in turn, named for
James Key Caird [1837–1916],
jute baron and philanthropist). He acted also as patron of the
British Schools Exploring Society (B.S.E.S.) from 1962 until his death in
Winchester. ==Personal life==