In 2005 he became the councillor to the Our Moldova Alliance parliamentary faction and held office by 2009. At the parliamentary elections held in April 2009, he was elected an MP from the lists of the Our Moldova Alliance.
By the Decree of the President of the Republic of Moldova no. 4-V of 25 September 2009 was appointed Deputy Prime Minister of the Republic of Moldova.
At the VIIIth Congress of "Our Moldova" Alliance, held on 12 December 2009, Victor Osipov was elected as the first deputy chairperson of the party.
In 2010, he participated at the parliament elections with the Our Moldova Alliance (No. 2 in the list). The Alliance did not exceed the 4% electoral threshold, accruing only 2.05% of the votes validly cast.
On 9 March 2011 Victor Osipov announced his withdrawal from the political activity, implicitly, from the position of first deputy chairperson of AMN ("Our Moldova" Alliance). In over a month the party "Our Moldova" merged with the Liberal Democratic Party of Moldova.
On 2 July 2014 Victor Osipov became the manager of the election campaign of the Democratic Party of Moldova for the parliamentary elections in the autumn 2014.[2]
From 18 February 2015 he serves as Deputy Prime Minister of the Republic of Moldova in the Gaburici Cabinet and then in the Streleț Cabinet.