Ian MacArthur was one of the more effective leaders of Scottish Unionism, although in a period when the party was in slow decline. Elected to Parliament in 1959, he was appointed an assistant whip in 1962 and promoted to be a Lord Commissioner of the Treasury and Scottish Whip in December 1963. He continued to serve as Scottish whip when the Conservative party went into opposition, but in October 1965 was made one of the front bench spokesmen on Scottish matters. Overlooked when Heath was constructing his government after the Conservative's election victory in 1970, he was made Vice Chairman of the Conservative Party in Scotland two years later, a post he held until 1975. The party had already lost ground to the Liberals and they now struggled to contain Scottish nationalism. MacArthur had been a proponent of the reforms that broke the power of the old East and West divisional councils and led to the creation of the Scottish Central Office in 1965, but although further reorganisation was carried through, the party lost further seats to the Nationalists, one of them McArthur's own, in February and October 1974. Gains elsewhere were only partial compensation.
MacArthur steered four Private Member's Bills on to the statute book, the most notable being the Domicile and Matrimonial Proceedings Act (1973), which, in Lord Denning's words, abolished “the last barbarous relic of a wife's servitude”. Until that point a woman separated from her husband was treated as having her legal domicile with him still. The remaining bills concerned themselves with the payment of damages and with social work in Scotland
Ian MacArthur was born on 17 May 1925, the younger son of Lieutenant-General Sir William MacArthur, and he was educated at Cheltenham College. Joining the Navy as an ordinary seaman in 1942, he was commissioned and saw active service with destroyers in the Mediterranean. To the end of his life suffered from deafness in his left ear as a result of bombardments during the Italian campaign. After the war he served as flag lieutenant to C-in-C Portsmouth (a role which, he later said, involved making himself invisible and saluting a lot). Amongst the friends he made at this time was Philip Mountbatten, soon to marry the Princess Elizabeth.
Demobilised in 1946, he took up his scholarship at The Queen's College, Oxford, to study modern languages, but then joined J. Walter Thompson, one of the major advertising agencies, in 1947, rising to become director of administration. He retained his connection with the firm as an Associate Director, apart from his time in office. He was elected an honorary member of the Institute of Practitioners in Advertising in 1963.
However, his real passion was for politics and he was elected to the Young Conservatives National Advisory Committee 1951-3 and the Conservative Party's National Advisory Committee on political education 1955-58. He fought Greenock in the 1955 General Election, cutting the Labour majority to 1,033 and was disappointed to see that extended to 2,694 in the bye-election which followed in December 1955. His reward for coming so close to capturing a Labour stronghold was selection for the safe Conservative seat of Perth and East Perthshire. He took the seat with a majority of 14,580 in the 1959 General Election and held it at four General Elections. When Sir Alec Douglas Home became leader of the Conservative Party in 1963, MacArthur was chosen to be his aide in the bye-election that returned him to the House of Commons. During his time in Parliament he served on the Speaker's Conference on Electoral Law, on the Scottish Select Committee, and on the Committee to scrutinise European legislation. He also chaired the Scottish Conservative Members Group 1972-3. While MacArthur was re-elected in the February 1974 General Election with the still comfortable majority of 8,975, he fell victim to the Scottish Nationalists in October, losing by 793 votes.
After his defeat, he did not long remain in party politics, but became the Director of the British Textile Federation in 1977. He was awarded the OBE in 1988 and retired in the following year. He had been appointed a Fellow of the Royal Society of Arts in 1984. He served as Treasurer of Texprint Ltd, a charity, from 1991 until 1998, acting also as its Vice Chairman from 1992.
A fluent French linguist and lifelong Francophile, MacArthur was also a fine musician. As a young man he had sung French songs in a number of nightclubs, accompanying himself on the piano, and his performances were good enough to earn him a recording opportunity. He made two records. He had married a nurse, Judith Douglas Miller in 1957 and they had four boys and three girls.
Ian MacArthur died on 30 November 2007.