Harbord commenced his political career with his election to the Great Yarmouth Board of Guardians in 1894 and was its chairman for four years.

He was a Justice of the Peace and served on many local government, other public and charitable committees.

In the Liberal split of September 1931 when Sir John Simon formed the National Liberal group in Parliament to continue giving support to the National Government of prime minister Ramsay MacDonald, Harbord decided to leave the official Liberals led by Herbert Samuel and join the Simonites.

He held Great Yarmouth as a Liberal National at the 1931 general election and again in 1935.

[4] He was appointed a CBE in 1935 for political and public service[5] and knighted in 1939.