From 1999 to 2001, Søviknes was the vice chairman of the Progress Party together with Siv Jensen, and was considered as a possible successor to Carl I. Hagen as chairman of the party. He however became controversial after an incident at a party congressin 2001 where he had sexually abused a 16-year-old intoxicated member of the Youth of the Progress Party. Søviknes retained his position as mayor of Os and did not lose his local support after the incident.
Mayor of Os
After first being elected mayor following the 1999 local elections, his local party's support subsequently surged from 36.6 to 45.7% in the 2003 local elections. The success was repeated in the 2007 local elections when he was reelected by a landslide. The candidate from the Conservative Party who came in second, jokingly commented that "You don't challenge Terje Søviknes in Os." He was yet again reelected in the 2011 local elections, this time however by a far lesser margin. This led to speculation that he could be ousted from power by a coalition of the other parties. Søviknes remained in power with the support of the Conservative party. Os has since by himself and the media been seen as a showcase municipality for the Progress Party. This is as he in his first term as mayor achieved full kindergarten coverage, full nursing home coverage and started a program of well-being and health journeys to Spain and related locations. It was also established a "full" stop of immigration and a local Vinmonopol store. Successful in being consecutively elected as mayor from 2003 to 2007, in this term the main issues was development of the city centre, better drug addiction recovery programs, development of schools and construction of a waterpark. While the municipality was struggling with large deficits before Søviknes became mayor, this has since been turned into a significant surplus as of 2004. His successful career as mayor of Os has gained him the nickname the "Wizard of Os" by the media.
Minister of Petroleum and Energy
On 20 December 2016 Søviknes was appointed Minister of Petroleum and Energy in the Solberg Cabinet, succeeding fellow party member Tord Lien.
Personal life
Søviknes married his first wife, Janniche Askeland in 1998 and they have two children together. In October 2011 they announced that they were separating. Søviknes is an avid bridge enthusiast and former president of the Os Bridge Club.
Awards
Zero Emission Resource Organisation's Local climate measure of the year : 2011
Norwegian Lifesaving Society's Badge of Honour: 1993