He was a last-minute choice as one of the
Liberal Party candidates in
Bath at the
1900 general election, but was defeated at the polls. At the
1906 general election, he stood again and was elected as a Liberal
Member of Parliament for the constituency. Whilst an MP, he voted in favour of the 1908 Women's Enfranchisement Bill. He lost his seat at the
January 1910 general election, but moved constituency at the
December 1910 general election and was returned for
Peebles and Selkirk, a seat he held until 1918. He then represented
Peebles and Southern Midlothian between 1918 and 1922, He also unsuccessfully contested
Kilmarnock in
1923 and
Cardiff East in
1924. Maclean was appointed a
Privy Counsellor in 1916, and was knighted in 1917. He was Leader of the Liberal Parliamentary Party from 1918 to 1920, as the leader of the
Liberal Party,
H. H. Asquith had lost his seat in the
House of Commons. For those two years he also served as
Leader of the Opposition, while
Labour had no official leader and
Sinn Féin had proclaimed the
Irish Republic and the
First Dail. Towards the end of his life, Maclean joined the
National Government headed by
Ramsay MacDonald. He served as
President of the Board of Education from 1931 to 1932.
Elections contested UK Parliament elections ==Personal life and death==