He was born in London as Henry Herman Schloesser, the son of a leather merchant and a concert pianist; he changed his name in 1914, preferring the Anglicised form when Britain went to war with Germany. After an apprenticeship in railway engineering, his health collapsed, and when he recovered he trained as a barrister. He also joined the Fabian Society, and his legal and political careers became entwined; much of his casework involved defending workers, and in 1912 he was appointed standing counsel to the Labour Party.
He was adopted by the York Labour Representation Committee to run as their candidate at the General Election expected to occur in either 1914 or 1915. The Fabian Society had agreed to finance his campaign. York was a two-member seat which had returned one Conservative and one Liberal MP in 1910. The Liberal and Labour parties had agreed to only put forward one candidate each, against two Conservatives, which would have given Schloesser a good chance of victory. However, due to the outbreak of war in Europe, the election did not take place.
He unsuccessfully contested the 1922 general election in Leeds Central, and was defeated again at a by-election in 1923 and at the December 1923 general election. He had grown wary of socialism, and based his campaigns on what he described as "medieval economics", principles drawn from his Anglo-Catholic religious faith; in his 1941 book Judgment reserved, he attributed his defeat in 1922 to the "secularist and Hebrew" elements in the constituency disliking the presence of monks among his supporters.
When Ramsay MacDonald's First Labour Government took office in January 1924, Slesser was appointed as Solicitor General. This was an unusual appointment, because the post had previously been offered only to Members of Parliament, and usually only to King's Counsel (KC). Before his appointment on 24 January, he was made a KC and knighted.
The government fell in October 1924, and at the 1924 general election Slesser was elected as Member of Parliament (MP) for Leeds South East. He was re-elected at the 1929 general election, when Macdonald formed a Second Labour Government. The new Lord Chancellor offered Slesser a post as judge in the Appeals Court, which he accepted.
Slesser died in 1979, aged 96. His wife Margaret, whom he had married in 1910, had died earlier that year.
- Political Change and the Labour Party 1900-1918 By Duncan Tanner
- Craig, F. W. S. (1983) . British parliamentary election results 1918-1949 (3rd edition ed.). Chichester: Parliamentary Research Services. ISBN 0-900178-06-X.
- Leigh Rayment's Historical List of MPs [self-published source][better source needed]
- Hansard 1803–2005: contributions in Parliament by Sir Henry Slesser
|Parliament of the United Kingdom|
|Member of Parliament for Leeds South East
1924 – 1929
|Solicitor General for England and Wales