Pauline Hanson's newest MP won't take his place in parliament for another few weeks while the the count in the southern NSW seat of Farrer is finalised, but the ramifications of David Farley's victory are already being felt in the coalition.
Former Liberal leader Sussan Ley held the seat for 25 years until her retirement from politics after she was ousted by her colleagues in February.
Opposition Leader Angus Taylor told a joint party room meeting on Tuesday that it was crucial for the coalition to take its medicine and learn from the loss.
"There is a perception that we've breached the trust of the people of Farrer," he said.
"We've been seen as parties of convenience, but not parties of conviction, and that conviction is going to be really key in us getting back to our first principles of what has made our party strong.
"With conviction must come consistency and unity, and if voters don't see that from us over the next year ... until the next election, then that is going to be a problem for us."
Two regional coalition MPs said voters perceive One Nation as the party that's "fighting" for them.
Nationals MP Michael McCormack, whose electorate of Riverina neighbours Farrer, conceded One Nation could pose a threat to him at the next election.
"I'd be silly to say I'm just turning a blind eye to what happened on the weekend," he told AAP.
"That's not me anyway, I've always treated the seat as though it's a marginal seat."
Pointing to his record as a long-serving local member, the former deputy prime minister said his days often start at 5.30am and continue well into the night.
He also took a swipe at Ms Ley.
"There are a lot of people who claimed they hadn't seen their local member for a while," Mr McCormack said.
After initially refusing to rule out joining One Nation, fellow National Colin Boyce on Monday said he was sticking with the regional party.
The Queensland MP, whose electorate includes Gladstone and some towns surrounding Rockhampton, said he was "obviously" concerned about the rise of One Nation and warned the party would find even less resistance in his area than it did in in Farrer.
"I'm absolutely sure it's alive, it's real," Mr Boyce said.
One Nation is also talking up its chances in outer suburban seats like Lindsay and McMahon in Sydney's west, but some analysts argue a higher number of multicultural voters could make it harder for the anti-immigration party to make inroads there.
One Nation MP Barnaby Joyce dismissed those claims, saying the cost of living and a lack of housing affected all Australians.
"Just because you might have more olive complexion doesn't mean you live in a different nation," he told Sky News on Monday.
"There is a huge opportunity."
One Nation's surge - if replicated nationally - will likely draw parallels to the boost in support for Nigel Farage's Reform UK party, which had more than 1400 candidates elected in England's recent council elections.
Senator Hanson's chief of staff James Ashby revealed Mr Farage had congratulated One Nation on its by-election win.
