Support for the Victorian opposition has dropped even further ahead of a crucial by-election in Melbourne's northeast.
The new Resolve Strategic poll, published in The Age shows the primary vote for the coalition at 26 per cent, compared to the Labor government's 41 per cent.
It was a drop in polling for the opposition, who received 30 per cent of the primary vote in the two Resolve polls published in February and April.
The latest results, published on Wednesday night, come ahead of a by-election in Warrandyte, triggered by the resignation of veteran MP Ryan Smith.
The seat is held by the Liberals on a 4.2 per cent margin.
Opposition Leader John Pesutto acknowledged it would be a difficult fight to retain the seat.
"We've got a government that's six months out from its third election victory in a row so it's going to be a tough contest," he told the Melbourne Press Club on Wednesday.
"We're going to throw everything at it and we'll campaign as hard as we can.
"I don't think it assists anybody by making predictions about what will happen."
The latest Resolve poll shows Mr Pesutto is also behind Daniel Andrews as preferred premier, sitting on 26 per cent of the vote compared to Mr Andrews' 49 per cent.
Mr Pesutto said he was confident he was the right person to lead the coalition into the next state election.
"We have a job to do - we've got to make ourselves a viable winning opposition," he said.
"We're sick of losing, we want to win."
The Warrandyte by-election is due to take place some time in August or September.
Labor is yet to announce whether it will contest the poll.
It will be the first Victorian state by-election in more than five years, and Labor hasn't won one since taking the seat of Benalla from the Nationals in 2000.
