Victorian Opposition Leader Brad Battin says the results of two weekend byelections have given his party confidence ahead of the next state election.

Vote counting will resume on Monday after a huge swing against Labor and a victory for the Liberals in a formerly Greens-held seat.

The two Victorian polls in Werribee in Melbourne’s west and Prahran in the city’s inner-east marked the first time Premier Jacinta Allan and new leader Battin were put to the test at the ballot box.

Labor traditionally holds Werribee but the party’s primary vote was down 16.7 per cent when counting was halted on the weekend.

The resignation of former treasurer Tim Pallas triggered the byelection.

By early Sunday morning, Liberal candidate Steve Murphy had 29.04 per cent of the primary vote, with Labor’s John Lister on 28.71 per cent.

But Murphy (49.45 per cent) was trailing Lister (50.55) on a two-candidate-preferred basis.

Meanwhile in Prahran – a Greens stronghold up for grabs after MP Sam Hibbins quit – Liberal candidate Rachel Westaway claimed victory on Sunday.

It is the first time the seat had changed hands in more than a decade.

Battin said the weekend results had given his party confidence ahead of next year’s state election

“I’m not confident we’ll win it (Werribee), but I’m very confident we’ve had a really good result,” he told ABC radio on Monday.

“There’s been a massive swing against Labor … I think we’ll end up with about a 4.5 per cent swing to us and that means we’ve got more work to do.

“If that result was reflected across Victoria, there would be a change of government at the next election in 2026.”

Victorian Greens leader Ellen Sandell blamed the loss on preferences and the byelection’s timing.

“Obviously, it’s not the result we would have liked but with the unofficial Labor candidate sending their preferences to the Liberals, those Labor preferences have handed the seat to the Liberals this time,” she said.

The Victorian Electoral Commission said there would be a recheck count of votes on Monday.

“This is a routine process after any attendance election, which involves rechecking each district ballot paper for correct counting and formality,” a spokesperson said.

-AAP