The Liberal Party has not fielded candidates in inner-Melbourne seats where the fight is between Labor and the Greens.
The Liberals formally lodged 77 candidates on Wednesday, but left out Brunswick, Richmond, Northcote and Melbourne.
Victorian Electoral Commission nominations close at midday on Thursday, meaning the party could still enter those four contests.
If not, the tactic would starve Labor of preferences in the marginal seats and potentially cost Premier Daniel Andrews a majority government.
The Greens have already flipped Melbourne and Northcote – as well as Prahran – and hopes to secure the balance of power on November 24.
Labor narrowly held on to Brunswick and Richmond in 2014 thanks to Liberal preferences, which favoured Labor over the Greens.
Shadow Treasurer Michael O’Brien said there was still time for candidates to be lodged with VEC.
“My advice is that the final decision will be made by the time of close of nominations,” Mr O’Brien told reporters on Wednesday.
“We will run our candidates and arrange our preferences in a way that we think as a party maximises our chance to win.”
He rejected that Liberal voters in those seats would prefer a Labor result to the Greens.
“You have the far left in the Greens, you have rorters in Labor. For a Liberal voter it’s between the devil and the deep blue sea.”
Negotiations for a preference swap had reportedly stalled when the Liberal Party lodged its candidates on Wednesday.
The party would lose $6 per vote in each of those seats under new election funding if it doesn’t run.
Liberal Party campaign director Nick Demiris on Wednesday said the election was “one of the most important in Victoria’s history”.
“This election is about who has the policies and ideas to get back in control of our population growth and fix our congestion, crime and cost-of-living issues,” Mr Demiris said in a statement.
“Victorians have a clear choice. They can vote for a stable, majority Liberal Nationals Coalition government, or for the chaos and dysfunction of a Labor Greens alliance.”
Brunswick Greens candidate Tim Read said his campaign was prepared whether Liberals run or not.
“First of all, we’ve always prepared for them running and our strategy is built on winning with them running,” Dr Read, a sexual health physician, told The New Daily.
“If they don’t run there could be a marginal benefit [to the Greens] there.”
The difference could be minimal, but with such a tight margin it could still decide the seat.
Dr Read is hopeful but said anything could happen on election day.
Richmond Greens candidate Kathleen Maltzahn suggested it was a bad look for the opposition not to represent itself in every electorate.
Ms Maltzahn lost to Labor’s high-profile Planning Minister Richard Wynne by just 1.86 per cent in 2014.
Liberals lodged Prahran candidate Katie Allen for the three-way contest. Greens sitting member Sam Hibbins faces a challenge from both Labor and the Liberals after flipping the formerly Labor seat in 2014 by a razor-thin margin of 0.37 per cent.