Maverick MP Bob Katter has given Malcolm Turnbull an extra number in parliament as federal election vote counting continues.
The prime minister met in Brisbane with the veteran north Queensland MP on Thursday, which ended with Mr Katter's pledge of support for budget supply and confidence when parliament returns in August.
The meeting came as the coalition appeared to be heading toward the slimmest of majorities - 76 seats in the 150-seat House of Representatives.
"Overall, I remain confident that we will form a government and we will ... unite the nation in a common purpose to continue to ensure that we have strong economic growth," Mr Turnbull said.
However, if the government ends up relying on Mr Katter's vote it won't be able to bank on his support for the two industrial relations bills that triggered the double dissolution election.
"If there is the slightest hint of union bashing, I can assure you all bets are off," Mr Katter said.
Based on Senate seat predictions, the government appears unlikely to get the bills through a joint sitting of parliament.
Tasmanian independent MP Andrew Wilkie said he had spoken to Mr Turnbull on Thursday, but insisted he would not be agreeing to any formal deals.
"It is in my electorate's very best interest that I have a good relationship with the man who is increasingly looking like he will remain as prime minister," Mr Wilkie said.
Independent MP Cathy McGowan's spokesman declined to comment on whether she would back supply and confidence.
The Greens' sole lower house MP Adam Bandt said his party would not support the coalition in government.
Nick Xenophon, whose team candidate Rebekha Sharkie won the seat of Mayo, says he is open to a formal agreement.
Labor leader Bill Shorten said he had also been talking to crossbench MPs in a bid to deliver on election promises and hold the coalition to account.
While he has not conceded, Mr Shorten told reporters in Perth it was more likely Mr Turnbull would be returned as prime minister.
Mr Shorten rejected the idea of Mr Katter providing stability to the government.
On Thursday afternoon, the government was holding 73 seats with Labor on 66.
Coalition gains now include Dunkley, Chisholm and Gilmore, with a lead of 440 votes in the Queensland marginal seat of Forde.
Labor was ahead in the Liberal-held seat of Flynn by 655 votes but postal votes were flowing strongly to government MP Ken O'Dowd.
The ALP was ahead in Capricornia by 472 votes, Cowan by 722, Herbert by 620 and Hindmarsh by 10.
But Hindmarsh was expected to be a coalition gain and Herbert a coalition hold.
Mr Shorten is set to have his authority endorsed by the Labor caucus at a meeting on Friday, but the leadership will be automatically spilled and opened to nominations.
However, there are no indications of a challenger.