Sir Thomas Legg spent his civil service career in backroom offices only to emerge into the glaring media spotlight heading one of Westminster’s most politically contentious public inquiries – the 2009 investigation into MPs’ expenses. The doorstepping and requests for interviews – both consistently rebuffed – were unwelcome but he was well-equipped to examine the misuse of public funds and not surprised by what he viewed as a decline in public standards. Legg, who has died aged 88 of kidney failure, had been permanent secretary in the Lord Chancellor’s Department, which administered the courts in England and Wales, and a member of both the Audit Commission and the House of Commons audit committee. Legg’s review had to assess 147,000 separate expense claims submitted by 752 serving and former MPs over a five-year period, deciding whether each was improper or not – including the notorious £1,645 paid out to the Tory MP Sir Peter Viggers for an ornamental duck island. The challenge for Legg was establishing uniform criteria that would be accepted and on which he could base value judgments about individual claims. An additional problem was the relationship between Commons fees officials and MPs, which he found involved “vague” rules and decisions often lacking legitimacy. His report recommended MPs return a total of £1.3m. Appeals against repayments, made to a former judge, Sir Paul Kennedy, who had been appointed by parliament, further reduced the total and prompted accusations from some MPs that the inquiry had been “sloppy” and “illogical”. Legg was disappointed the figure was less than the cost of his inquiry. He believed thrift in government was a virtue. In a 2002 obituary written for the Guardian of a former colleague, Hume Boggis-Rolfe, Legg had praised his “economies great and small” and his practice of keeping “a desk-drawer full of old pieces of paper and string for re-use, so that the public funds should not be wasted”. Tom Legg was born in London. His father, Stuart, was an Oscar-winning documentary film-maker, and his mother, Margaret, was the daughter of Sir Maurice Amos, a barrister and law professor. Stuart, who had been with the pioneering GPO Film Unit run by John Grierson, transferred to the National Film Board of Canada in 1939 and the family moved to New York. Tom was educated there at Horace Mann-Lincoln school but returned to Britain in 1948 and was sent to the co-educational Frensham Heights boarding school in Surrey. He completed two years’ national service (1953-55) as a junior officer in the Royal Marines before attending St John’s College, Cambridge, where he studied history and law. In 1960, he was called to the bar and practised as a barrister. Two years later he received a letter inviting him to join the Lord Chancellor’s Department, which then ran the judicial system in England and Wales. The office in the House of Lords, he later recalled, “consisted of 12 white male barristers, all dressed in black jackets, striped trousers and stiff white collars”. He enjoyed the collegiate atmosphere. The rest of his full-time career was spent in the expanding department. He became private secretary to the lord chancellor, Gerald Gardiner, in the mid-1960s and was thrilled to be involved in the negotiations that led to the UK entering the Common Market. In the 80s, he was given responsibility for appointing judges and QCs. From 1989 to 1998, Legg was the permanent secretary. He himself was appointed a QC in 1990, and he was knighted in 1993. The department was subsequently absorbed into the Ministry of Justice. After retiring from the civil service in 1998, Legg was entrusted with heading the inquiry into allegations that a British company, Sandline, International had shipped arms to Sierra Leone in contravention of a UN embargo. The report concluded the firm had been given tacit approval by senior Foreign Office officials. Two other high-profile inquiries followed: Legg’s investigation of the overspend on Portcullis House, built to provide office space for MPs next to parliament, and his reputation-shattering examination of MPs’ expenses. He was also chair of the Hammersmith Hospitals NHS Trust, chairman of the London Library and on the council of Brunel University. Brexit was a bitter disappointment. In a 2017 speech, he worried about the independence of the judiciary in an era when it had “made new inroads into the world of government” and the “political class and the legal class have moved further apart”. His book, An Unwritten Rule: How to Fix the British Constitution, 2021, co-authored with Lord (Stephen) Green of Hurstpierpoint and Sir Martin Donnelly, called for greater devolution to English regions and cities. Legg enjoyed dining with friends at the Garrick Club. At over 6ft 3in, he could appear daunting, but was invariably described as courteous. Legg married four times. Two marriages ended in divorce. His third wife, Maggie Wakelin-Saint, a retired lawyer, whom he married in 2009, died in 2013. He is survived by his fourth wife, Elizabeth Thompson, a former civil service lawyer, whom he married earlier this year, and by two daughters, Lucy and Isobel, from his second marriage, to Patricia Dowie, two grandchildren, Conrad and Jude, and by his sister, Ruth. • Thomas Stuart Legg, barrister and civil servant, born 13 August 1935; died 8 October 2023