The Liberals' internal polling consistently showed the Coalition could win a third term, and that its fortunes turned around immediately after the budget with its promise of a surplus to give it a "pathway" to election day.
The internal polling will add to calls for the nation's pollsters to face greater transparency and overhaul their number-crunching. None of the major national pollsters accurately forecast Saturday's result, with all putting Labor in a winning position. Combined, Newspoll, Ipsos, Essential and Morgan had Labor 51.7 to 48.3 in front on a two-party preferred basis.
But the federal director of the Liberal Party, Andrew Hirst, said its internal polling had shown for weeks a "pathway" to victory, albeit a "precarious and narrow one".
The Coalition's track polling of 20 marginal seats - 15 of them Coalition-held - showed Prime Minister Scott Morrison was poised to win right up until the final survey, which landed in Mr Hirst's inbox last Friday morning.
"Our last track had our primary up to 43 and Labor's down to 33," Mr Hirst told The Sydney Morning Herald and The Age.
The Australian Electoral Commission's most recent figures, published on Tuesday afternoon, had Labor's nationwide primary vote at 33.87 per cent and the combined primary vote of Coalition parties at 41.44 per cent.
The Liberals' polling was conducted by Michael Brooks, a London-based pollster with Crosby Textor who was brought out from the United Kingdom for the campaign.
His work showed 2 per cent of voters remained undecided and there was a "soft" vote of 13 per cent, which indicated 15 per cent of voters were still up for grabs 24 hours before election day.
"We kept [the polling] very tight, it was deliberate, it was very deliberate," Mr Hirst said.
The internal Liberal Party results were in stark contrast to the published polls, including Saturday's exit poll and Friday night's Newspoll, which reported the two-party preferred split was 51.5 per cent to 48.5 per cent in Labor's favour.
The election-eve poll, which is renowned for matching the election-day results, sent jitters through Liberal Party operatives who feared they had missed seats they could lose.
Mr Hirst said the Coalition experienced a crucial "reset" with April's budget - something else that was missed by published polls - but would remain dependent on internal discipline and a focus on attacking Labor's tax agenda.
Internal research showed the government's commitment to get the budget back to surplus cut through with voters and provided a sustained bounce in the Coalition's primary vote.
Mr Hirst said this provided the "logical underpinning" for the Coalition's attack on Labor's proposed changes to negative gearing, capital gains tax concessions and removing franking credits.
"The foundation for our argument around tax, it was 'Yes, they're going to tax you more and it's going to hurt, you'll pay more', but it was also 'Labor can't manage money so they'll come after yours," he said.
The promised budget surplus also sent a message to voters that the Coalition could manage the economy. Once the party stopped its internal bickering, it was able to focus its efforts on applying pressure on Labor.
The combined effect of the budget and the Coalition's renewed attack on Labor began shifting the mood in the electorate just as Mr Morrison called the election.
Internal research showed the Coalition ahead in the Labor-held seats of Lindsay, Herbert and Bass early on in the campaign, giving the Liberals hope for Braddon, a similar electorate. Each of those seats was won by the Coalition on Saturday.
With two weeks to go until election day, polling also showed the Liberal National Party ahead in the Queensland seat of Longman, reversing last year's byelection result, which was used as a reason to topple former prime minister Malcolm Turnbull. It was also won by the LNP.
- SMH/The Age