In parliament he mainly spoke on issues of administrative and constitutional law. He was a very influential member of parliament. When the law concerning the decolonisation of Indonesia, a very controversial issue, was voted on, the two-thirds majority was only reached because an amendment proposed by Oud ensured the support of the VVD. In 1950–51 Oud came into conflict with the VVD's Minister of Foreign Affairs, Stikker, over the policy concerning Netherlands New Guinea. Between 1950 and 1953 he was a member of the Government Committee Van Schaik, which prepared a constitutional change. In 1952 he did not seek to be reappointed as Rotterdam's mayor, and instead became extraordinary professor of Constitutional Administrative law at the University of Rotterdam, which he remained until 1957. Between 1953 and 1963 he was chair of the Justice Committee of the House of Representatives. As such, he was heavily involved in the preparation of many laws, and served as chair on the committees preparing the laws on the provinces, the police, archives, patents and many more. In 1959 he came into conflict with Harm van Riel, the chair of the VVD's parliamentary party in the Senate, because Van Riel wanted to become minister, but Oud denied him this.
