 Jenkins was first elected to Parliament at the 1922 general election as a National Liberal.He was elected to represent Breconshire and Radnorshire which he won in a straight fight with Labour.At the 1923 general election he was returned unopposed as a Liberal (without suffix or prefix) for the same seat but in 1924 he faced a three-cornered contest against Labour and Conservative opposition and he lost the seat to the Tories.