Mayencourt is seeking the party's nomination in the riding of Vancouver-False Creek, and he could be in for a fight.
Former Vancouver mayor Sam Sullivan has also announced he is going to vie for the nomination to stand in next May's general election.
Mayencourt has already represented the Liberals in the B.C. legislature twice in Vancouver-Burrard. After his first stint, he quit in 2008 to take a run at a federal seat, which he lost.
He then ran again successfully provincially.
Mayencourt has spent the past 18 months working behind the scenes for the government caucus, and says he is ready for another campaign.
"I think we have some great opportunities that are ahead of us economically, socially, and I want to be part of the mix that brings that to British Columbia."
Mayencourt says fresh faces are important for a government that's been in power for more than a decade.
"We need to change what our backbench and our frontbench looks like and this opportunity that comes forward in 2013 is going to be a significant opportunity."
Mayencourt is probably best known for his “safe streets” legislation, which attempted to crack down on aggressive panhandling.
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