[1] On the same day he was appointed a Knight Commander of the Order of the British Empire (KBE), for services to national security and civil liberties, in the Queen's 2018 Birthday Honours.
Anderson came to the English Bar after spells in Washington DC (1985–86) as a lawyer from abroad at Covington and Burling and in Brussels (1987–88) in the private office of Lord Cockfield, the European Commissioner tasked with completing the Internal Market.
His cases in the highest UK courts include ProLife Alliance v BBC (freedom of political speech) and Heathrow Airport's appeal in relation to the national policy statement governing the construction of its third runway.
[28] "A Question of Trust",[29] Anderson's June 2015 report of his Investigatory Powers Review, described the obscurity of the then law as "undemocratic, unnecessary and – in the long run – intolerable".
The report was described in an opinion piece by an editor at The Guardian as "the turning point that policymakers have looked for and missed ever since 9/11",[30] and was a blueprint for the Investigatory Powers Act 2016.
[50] His report, which appraised the numerous recommendations for operational improvements arrived at by MI5 and the police with his input, was published in December 2017,[51] with a follow-up "stock-take" in June 2019.
He gave his maiden speech on 19 July 2018 in a debate on the impact of referendums on parliamentary democracy,[55] and began to contribute on issues ranging from national security,[56][57][58] internet safety[59] and surveillance[60] to EU-related and constitutional matters.
[61][62][63] He moved the amendment in July 2019 that limited the Government's scope to prorogue Parliament,[64][65][66] and spoke and wrote against the dangers of populism[67] and of a no-deal Brexit.
[92] He opposed a government amendment to the Levelling-up and Regeneration Bill, which would have conferred a broad delegated power to regulate the discharge of nutrients into protected waterways.
[97] In the 2023-2024 parliamentary session, Anderson welcomed (with a few reservations)[98][99] the Investigatory Powers (Amendment) Act 2024,[100] which was based on proposals endorsed in his own report of 2023.
[104] In the same session he signed an amendment to prohibit foreign governments owning UK newspapers,[105] which bore fruit in the Digital Markets, Competition and Consumers Act 2024,[106] and sought to limit proposals in the Data Protection and Digital Information Bill, which fell when the 2024 General Election was called, for the indiscriminate gathering of banking data to counter social security fraud.
[110] Anderson has spoken and written about topics ranging from genocide,[111] the Northern Ireland Troubles,[112] treason[113] and artificial intelligence[114] to scrutiny of international agreements[115] and the dangers of executive over-reach.
[134] Anderson has been since 1999 a visiting professor at King's College London and is a former General Editor of the OUP's Oxford European Union Law Library.
[137] Since July 2019 Anderson has chaired Inter Mediate, a charity founded by Jonathan Powell which seeks to resolve some of the most difficult, dangerous and complex conflicts worldwide.
It bears the names of Anderson's great-great-uncle Eric Milroy (Scotland's captain in 1914, killed at Delville Wood in July 1916) and of his French counterpart, the aviator Marcel Burgun.