Tizard was the Member of Parliament for Tamaki for the next three years. For the duration of the Second Labour Government Tizard was a backbencher. In the dying days of the government, Prime Minister Walter Nash overruled security services advice and approved the naturalization of a European emigrant living in Tizard's constituency who had in his youth been linked with Marxist circles, but had lived in New Zealand for many years and had a New Zealand wife and children. The police had not given him a clearance because, in their view, he had not accepted "New Zealand ideals". Nash minuted in 1960 that he should be allowed to naturalise. The file lay on his desk without action for many months however. Tizard found the file and took it to the Minister of Internal Affairs, Bill Anderton (who was the only minister in Wellington during the 1960 election period because he was not standing) and he signed the necessary approval. At the 1960 general election he was defeated by National's Robert Muldoon. Thereafter Tizard and Muldoon developed an intense rivalry with each other, occasionally bitter.