McCartney is one of the founders of and the leader of the Democratic National Alliance political party.

[1] He previously served in the Cabinet of the third Ingraham administration, but resigned before the 2012 general elections were called.

He later attended Holborn Law College, graduating in 1989 with an LL.B honours degree and was subsequently admitted to the Bar of England and Wales at the Inner Temple and the Bahamas Bar in 1990.

In 2000, McCartney started his own law firm, Halsbury Law, which hosts an annual free legal clinic, the only one in the country opened to the general public.

[3] He resigned after two years and founded a new political party the Democratic National Alliance.