Question: When was the British Labour politician Which was one of those investigated by David Shayler born? 
Context: Stanley Clinton Clinton-Davis, Baron Clinton-Davis, PC (born 6 December 1928), born Stanley Clinton Davis, is a British Labour politician, former European Commissioner, former minister and solicitor.  He served as Member of Parliament (MP) for Hackney Central (1970–1983), and was a minister in the Labour governments of Prime Ministers Harold Wilson, James Callaghan and Tony Blair.  He was European Commissioner in the Delors Commission (1985–1989).  In 1990, he became a Life Peer as Baron Clinton-Davis of Hackney, in the London Borough of Hackney, sitting on the Labour benches in the House of Lords, and changed his name to Stanley Clinton-Davis by deed poll. Iain McNicol (born 17 August 1969) is a British Labour politician and trade unionist.  He is the General Secretary of the Labour Party, the most senior employee of the Labour Party, following on from being National Political Officer of the GMB Union, and has a long history of organising in both the Labour Party and the trade union movement. George Alfred Brown, Baron George-Brown, {'1': ", '2': ", '3': ", '4': "} (2 September 1914 – 2 June 1985) was a British Labour politician who served as Deputy Leader of the Labour Party from 1960 to 1970 and also in several Cabinet posts, including Foreign Secretary during the Labour government of the 1960s.  He was a leader of the Labour Party's trade union right wing, and an effective election campaigner.  Ultimately, however, he was unable to cope with the pressures of high office without excessive drinking.  He was always known simply as "George Brown" and, upon being granted a peerage in November 1970, he insisted on combining his first name and surname to create the title Baron George-Brown of Jevington in the County of Sussex. Clement Richard Attlee, 1st Earl Attlee, {'1': ", '2': ", '3': ", '4': "} (3 January 1883 – 8 October 1967) was a British Labour politician who served as Prime Minister of the United Kingdom from 1945 to 1951 and Leader of the Labour Party from 1935 to 1955.  In 1940, Attlee took Labour into the wartime coalition government and served under Winston Churchill, becoming the first person to hold the office of Deputy Prime Minister of the United Kingdom.  He went on to lead the Labour Party to an unexpected landslide victory at the 1945 general election; forming the first Labour majority government, and a mandate to implement its postwar reforms.  The 12.0% national swing from the Conservatives to Labour was unprecedented at that time and remains the largest ever achieved by any party at a general election in British electoral history.  He was re-elected with a narrow majority at the 1950 general election.  In the following year, Attlee called a snap general election, hoping to increase his parliamentary majority.  However, he was narrowly defeated by the Conservatives under the leadership of Winston Churchill; despite winning the most votes of any political party in any general election in British political history until the Conservative Party's fourth consecutive victory in 1992.  Attlee remains the longest-ever serving Leader of the Labour Party. Peter Benjamin Mandelson, Baron Mandelson {'1': ", '2': ", '3': ", '4': "} (born 21 October 1953) is a British Labour politician, president of international think tank Policy Network and Chairman of strategic advisory firm Global Counsel. Margaret Beryl Jones, Baroness Jones of Whitchurch (born 22 May 1955) is a British Labour Peer and previously a trade union official and Labour politician.  She was Chair of the Labour Party from 2000 to 2001. Peter David Shore, Baron Shore of Stepney, PC (20 May 1924 – 24 September 2001) was a British Labour politician and former Cabinet Minister, noted in part for his opposition to the United Kingdom's entry into the European Economic Community.  His idiosyncratic left-wing nationalism led to comparison with the French politician Jean-Pierre Chevènement.  He was described in an obituary by the Conservative journalist Patrick Cosgrave as "Between Harold Wilson and Tony Blair, the only possible Labour Party leader of whom a Conservative leader had cause to walk in fear" and, along with Enoch Powell, "the most captivating rhetorician of the age". Ernest Bevin (9 March 1881 – 14 April 1951) was a British statesman, trade union leader, and Labour politician.  He co-founded and served as general secretary of the powerful Transport and General Workers' Union from 1922–40, and as Minister of Labour in the war-time coalition government.  He succeeded in maximizing the British labour supply, for both the armed services and domestic industrial production, with a minimum of strikes and disruption.  His most important role came as Foreign Secretary in the post-war Labour Government, 1945–51.  He gained American financial support, strongly opposed Communism, and aided in the creation of NATO.  Bevin's tenure also saw the end of the Mandate of Palestine and the creation of the State of Israel.  His biographer, Alan Bullock, said that Bevin "stands as the last of the line of foreign secretaries in the tradition created by Castlereagh, Canning and Palmerston in the first half of the 19th century," and that due to the reduction in British power he has no successors. David Shayler (born 24 December 1965) is a British former MI5 officer.  Shayler was prosecuted under the Official Secrets Act 1989 for passing secret documents to "The Mail on Sunday" in August 1997 that alleged that MI5 was paranoid about socialists, and that it had previously investigated Labour Party ministers Peter Mandelson, Jack Straw and Harriet Harman. Dennis Edward Skinner (born 11 February 1932) is a British Labour politician who has been Member of Parliament (MP) for Bolsover since 1970.  He was Chairman of the Labour Party for one year from 1988–89 and served as a member of Labour's National Executive Committee, with brief breaks, for thirty years.
Answer: 21 October 1953