Liberal state director Damien Mantach said on Wednesday evening that he would be standing down as state director to take up a position in the federal system.

"This is not a decision I have taken lightly, but I believe the time is right for change," Mr Mantach said. "While last year's election loss remains a bitter disappointment, we must learn from the reasons why we lost and be a strong and disciplined opposition in the lead up to the 2018 Victorian election."

Mr Mantach said he strongly believed Opposition Leader Matthew Guy would put the party in a "strong position" to return to government in 2018.

The Napthine government became Victoria's first single-term government since 1955, losing to Labor 48 to 52 per cent in two-party-preferred terms at the November 29 election.

A review of the state election campaign being undertaken by the Liberal Party is believed to spread the blame for the defeat widely, including raising concerns about the Coalition's media strategy, a dubious advertising assault on Labor, and the negative impact of the federal government.