As a member of the Likud Party, Hirschson joined the Knesset as a mid-term replacement in June 1983 and served until the end of the 10th Knesset in July 1984. He rejoined the Knesset in 1992, having been elected to the 13th Knesset, and has served since then. On 10 January 2005, he replaced Gideon Ezra as Minister of Tourism. In late November 2005, he resigned from the Likud and joined Kadima. On 18 January 2006, he was appointed Minister of Communications while retaining the Tourism ministry. That appointment filled one of the vacancies left by the resignation of all Labour Party ministers in November 2005, the act that resulted in the calling of elections for March 2006.