Leslie Knox Munro was born in Auckland on 26 February 1901, the son of Colin Robert Munro, a schoolteacher, and his wife, Maria Caroline Knox. He was educated at Remuera School and at Auckland Grammar School. At 19 he began law studies at Auckland University College. He initially worked for the law firm Jackson, Russell, Tunks and Ostler as an office boy at 10 shillings a week. However, after a few weeks he was awarded a university scholarship and spent a year studying full time at university before returning to the firm. He eventually graduated LLM in 1923. His admission to the Bar was moved by Vincent Meredith, whom he served as a clerk.
From 1924 to 1938 Munro lectured in constitutional law and Roman law at Auckland University College. He became dean of the law faculty in 1938. He also served on the university council from 1939 to 1951 and on the Senate of the University of New Zealand from 1947 to 1951. In Auckland, on 12 October 1927, he married Christine Mary Priestley; she died in August 1929, three days after the birth of a daughter. On 9 November 1931 Munro married Muriel Olga Sturt in Auckland; they were to have one daughter.
Munro was president of the Auckland District Law Society from 1936 to 1938, the youngest practitioner at the time to have held the office; he was also a member of the New Zealand Law Society council from 1936 to 1939. For three years before the Second World War he gave fortnightly talks on international affairs for the National Broadcasting Service, and from 1939 he contributed weekly articles on world events to the Weekly News. He also wrote editorials for the New Zealand Herald and in 1940 was asked by Henry Horton, of the publishers Wilson and Horton, if he would edit the paper. Munro became associate editor in 1941, then editor from 1942 to 1951.
A member of the New Zealand National Party from its formation in 1936, Munro served as president of the Remuera branch from 1938 to 1941 and as a member of the party’s dominion executive in 1940–41; he resigned from the executive on joining the New Zealand Herald. He described himself as belonging to some extent to National’s inner circle and as such played a role in Sidney Holland becoming leader of the party. National won the election in 1949 and in 1952 Holland appointed Munro as New Zealand ambassador to the United States and permanent representative of New Zealand to the United Nations. While permanent representative he became president of the Trusteeship Council (1953–54), New Zealand representative on the Security Council (1954–55) and president of the 12th session of the General Assembly (1957–58).
Munro took over the presidency of the Security Council during a heated debate over Egypt blocking the Suez Canal to Israeli shipping. Between speeches he shuttled next door to the Trusteeship Council and flew to Washington to carry out his duties as ambassador. As president of the Security Council he extended the practice of summing up the council’s views at the end of the debate, instead of accepting a formal resolution that required a vote and sometimes led to a veto.
Munro was knighted KCMG in 1955 and KCVO in 1957. With the election of the second Labour government in late 1957 his term as ambassador and permanent representative came to an end in 1958. The post was left vacant for some time and there was criticism that his term was not extended at least until a new appointment was made.
However, the United Nations appointed him its special representative on the Hungarian question; his role was to secure compliance with the United Nations resolutions on Hungary, including the withdrawal of Soviet forces, free elections and respect for human rights. He was refused entry to Hungary and the letters he addressed to the Hungarian and Soviet representatives at the United Nations were returned without reply. For information on what was happening in Hungary he had to rely on reports from refugees, foreign embassies and European capitals, and from newspapers behind the Iron Curtain. He held the position of special representative until 1962.
From 1961 Munro was also secretary general of the International Commission of Jurists. The aim of this body was to defend the rule of law throughout the world and work towards the observance of the United Nations Declaration of Human Rights. He remained in the United States until 1963. Over the years he had been in demand as a speaker throughout the country and had been awarded honorary degrees from several universities, including Harvard and Michigan. His work with the United Nations undoubtedly attracted international attention to New Zealand. In 1960 he published United Nations: hope for a divided world .
After returning to New Zealand Munro became a member of Parliament, winning the Waipa seat as a National candidate in 1963 and holding it in 1966. He became the member for Hamilton West in 1969 and retired from politics in 1972. In Parliament he served on the external affairs, statutes revision and education committees, but never rose beyond the back benches.
Munro privately, and probably correctly, attributed his failure to attain cabinet rank in nine years in Parliament to what he saw as the intense resentment his leader, Keith Holyoake, felt towards him rather than any reflection on his ability, experience and loyalty. Munro’s belated entry into Parliament was possibly another factor. Holyoake’s successor, John Marshall, who excluded Munro from his 1972 cabinet in the interests of promoting younger people, later wrote that Munro in his own mind ‘saw himself as prime minister, and in other times he might have been, but Keith Holyoake would not even have him in cabinet’.
The Dominion , which felt there was more to Munro’s omission from cabinet than charitable phrases about ‘coming too late to Parliament’, thought he was ‘in some ways a vain and egotistical man’ who did not suffer fools; he was described elsewhere as a ‘brilliant, idiosyncratic personality’. Although many in the Auckland and Waikato divisions of the party thought he should be in cabinet because of his unrivalled experience in international affairs, his inclination to go his own way as ambassador had not endeared him to the party’s leaders. Moreover, what was perceived as arrogance had upset some people, including Holyoake.
Intellectually and physically impressive, with dark bushy eyebrows, Munro was an incisive, elegant and often witty debater in the House. He gave his valedictory speech on 20 October 1972 wearing a waistcoat in the Munro tartan with gold buttons. The Evening Post reported, ‘His audience on both sides of the House hung on to every word and gesture as if they had paid top West End prices for the privilege’. Munro spoke without evident rancour over his failure to achieve a seat at the cabinet table, saying only, ‘I think it is inevitable and proper under our constitution that the Prime Minister should select his colleagues because he has to get on with them; it is a situation I accept’.
Sir Leslie Munro died in Hamilton on 13 February 1974, survived by his wife and daughters. Parliament took the unusual step of adjourning as a tribute. He had been one of New Zealand’s most distinguished citizens and his exclusion from cabinet in no way diminished his illustrious career. As the Evening Post commented, ‘Sir Leslie may well have consoled himself with the thought that it is more flattering for people to wonder why a person hasn’t been appointed a Minister than to wonder why he has’.