James Duncan Millar was one of the few men to become a member of both the Scottish and English Bars. He was admitted to the Faculty of Advocates in Edinburgh in 1896 and in the following year was called to the English Bar at the Middle Temple. He obtained a large practice in Scotland and was Senior Advocate Depute from 1913–1916. He was made a King's Counsel in Scotland in January 1914.
In 1931, an economic crisis led to the formation of a National Government led by Labourprime ministerRamsay MacDonald and initially supported by the Conservative and Liberal parties. However the Liberals were increasingly divided over the issue of the National Government, particularly over the policy of Free Trade. The official party led by Sir Herbert Samuel although agreeing to go into the 1931 general election supporting MacDonald became increasingly alarmed about the government's stance on Free Trade and worried about the predominance of the Conservatives in the coalition. However a group of Liberal MPs led by Sir John Simon who were concerned to ensure the National Government had a wide cross-party base formed the Liberal National Party to more openly support MacDonald's administration. Millar was not one of the founding members of the Liberal National Party but his endorsement of the government's programme was enough to ensure the Conservatives did not put up a candidate against him in East Fife in 1931 and on 16 October 1931, Millar found himself returned unopposed to represent East Fife in the next Parliament. He then chose to support the administration loyally and continued to describe himself as a Liberal National when the Samuelite Liberals withdrew from the coalition. He continued to enjoy the support of both the local Liberal and Conservative Associations in East Fife, with both of which organisations he had gained the reputation for being a good constituency MP, particularly in representing the interests of fishing and agriculture. Millar died in office at the age of 61. At the by-election held on 2 February 1933 to fill the East Fife seat following Millar's death, the local Liberal Association selected the Simonite James Henderson-Stewart to fight the seat. Standing as a Liberal National, Henderson-Stewart easily held the seat with a majority of 9,135 votes. He did not face Conservative opposition but there were four other candidates, including Labour, Agricultural Party, Independent Liberal and National Party of Scotland.
Honours
In 1913, Millar was appointed by the Secretary of State for the Colonies to sit on a committee of experts to look into the spread of various diseases in Africa and how they could be controlled. Millar was knighted in the 1932 New Year Honours for political and public services.
Death
Millar died at his home, Remony Lodge, Aberfeldy in Perthshire, following a period of some weeks suffering badly with phlebitis and complications.