Opposition Leader Peter Dutton has vowed to remain in the driver's seat and fight on after a historic by-election loss.
Labor claimed the eastern Melbourne electorate of Aston, the first time a government has won a seat from an opposition candidate at a by-election in more than 100 years.
Mr Dutton says the party will go through some soul-searching.
"We have a lot of work to do, I accept responsibility as I'm the leader of the party," he told the ABC's Insiders program on Sunday.
"Now, the question is how we rebuild from here, the policies that we have, the brand rebuilding that we need to do in Victoria.
"I can tell you it makes me more determined to rebuild this party and be in a winning position by 2025."
The opposition leader said state issues also played into the result with a dominant Labor government, and acknowledged inner-Melbourne seats had always been tough to win for the Liberals.
"Obviously, the difficulties for us in Victoria haven't germinated in Aston over the course of the last five weeks," he said.
"Even back to 2013, with all of my predecessors, Victoria is the one state that we have never held a majority of seats in and there are huge issues at a state level as well."
Nations leader David Littleproud said Mr Dutton remained the best person to lead the opposition.
"Peter is by far the best leader of the Liberal Party," he said.
"I think sadly what I saw in this election was the personal character assassination that I thought stooped to a level that Australian politics shouldn't."
He also blamed the local Liberals after weeks of infighting over a state MP attending an anti-transgender rally where neo-Nazis were also in attendance.
"The Victorian Liberal Party did everything they could locally there to trash their own brand."
Liberal candidate Roshena Campbell was also criticised for not living in the electorate.
Mr Littleproud said there were lessons for the Liberals to learn.
"The candidate probably not being a local shows that we have got to respect the local electorate and understand that they want someone local," he added.
Senior Liberal frontbencher Jane Hume also backed her leader after the historic loss.
"I cannot imagine there would be any mood in the party room for (a change of leader)," she said.
"There is no doubt this is a blow but he is a leader with a solid team behind him."
Mr Dutton said he led a united team, which was hard from opposition after an election loss.
"Parties always tear themselves apart in opposition. We haven't gone through that period of self-destruction," he said.
"I have a leadership style which I believe they appreciate which is why people very strongly are expressing their support to me."
