Lånke was elected to the Norwegian Parliament from Sør-Trøndelag in 1993, and has been re-elected on three occasions. On the local level he was a member of Trondheim city council from 1991 to 1993.
Lånke was the chairman of the Youth of the Christian People's Party, the youth wing of the Christian Democratic Party, from 1975 to 1976. Since 1997 he has been a member of the national Christian Democratic Party board.