He was first elected to the Knesset in the 1999 elections on the National Religious Party list. After being re-elected in the 2003 elections, Orlev was appointed Minister of Welfare and Social Services in Ariel Sharon's government. During the crisis in the party over the Gaza disengagement plan, Orlev led the camp which believed staying in the government, rather than leaving the coalition, was the best option. In response, NRP leader Effi Eitam called Orlev a "Meimadnik". When Eitam and Yitzhak Levy quit the government in 2004, Orlev and many NRP members refused to leave the coalition. Orlev then succeeded in taking control of the party, resulting in Eitam and Levy leaving to form the Renewed Religious National Zionist Party (later renamed Ahi), which would later join the National Union.