In his book "Referendum" (Tom Stacey Ltd, 1971) he argued that the referendum, then under discussion in the context of the United Kingdom (UK) joining the European Economic Community (EEC), could in fact serve to entrench constitutional safeguards that the UK then – as now – lacked, quoting Arthur Balfour's contribution to the debate on the Parliament Bill (later the Parliament Act 1911): "In the referendum lies our hope of getting the sort of constitutional security which every other country but our own enjoys ..." ("Referendum", ). He wrote the definitive account of the referendum campaign in 1975, "Full-hearted Consent", and also "The 1922: The Story of the 1922 Committee" (with Ursula Branston; Macmillan, 1973). He was a junior Northern Ireland minister (1979–1981) and a junior defence minister (1981). He was a member of the Founding Council of the Rothermere American Institute at the University of Oxford.