Career
However, when sought re-election as a National Liberal at the 1922 general election, he lost the seat by only 201 votes to the Labour Party candidate William Watson. Wallace stood again at the 1923 general election, this time as a Liberal, but Watson increased his majority. He did not stand in the 1924 or in 1929 elections, but contested the seat again at the 1931 general election, this time as a Liberal National.
He did not stand for Parliament again.
He was knighted in the New Year Honours 1935, for "political and public services".