 Following boundary changes, he was elected to represent Caernarvon at the 1950 General Election, defeating the Liberal candidate by over 10,000 votes.He continued to represent the constituency until February 1974, when he lost his seat to Dafydd Wigley of Plaid Cymru.During the 1950s, Roberts was, together with Cledwyn Hughes and others, a stalwart of the Parliament for Wales campaign.