In 1969, Roderick was chosen as Labour candidate for Brecon and Radnor, in succession to Tudor Watkins, who had held the seat since 1945.
[1] Roderick proved to be an assiduous and active constituency member, campaigning to prevent further rail closures and the proposed creation of a reservoir which would entail the flooding of the Senni Valley.
[1] Labour's main strength in the constituency lay in the industrial townships in its southern extremities, including Roderick's home village of Ystradgynlais.
[1] Following Labour's return to office in 1974, Roderick became successively parliamentary private secretary to Eric Heffer, Tony Benn and, from 1975, Michael Foot.
[1] He also opposed the Vietnam war and apartheid in South Africa and was a member of the Tribune group of Labour MPs.