3News political editor Patrick Gower said National's campaign had lurched from one crisis to another, and the latest poll showed it was now entering "the disaster zone".
"They could still save it, and John Key turning up will be a boost. But, to use cricketing terminology, he'll have to hit a six off the final ball."
Mr Osborne told the Advocate the figures were a surprise and did not reflect the feeling he was getting on the streets.
"We're getting a really positive response. But the reality is it's everyone versus us, so it's a challenge ... I guess we'll find out on Saturday."
Mr Osborne said the poll was a few days old and he believed his campaign was building momentum.
Poll respondents were also asked whether they considered National's 10 bridges programme an electoral bribe. Just under three-quarters (74 per cent) said yes, 22 per cent said no, and 4 per cent didn't know.
More than half (58 per cent), however, agreed with the bridge improvements while 39 per cent disagreed and 3 per cent were unsure.
The only bad news for Mr Peters was trust.
Almost half (48 per cent) said they didn't trust the NZ First leader; 43 per cent did trust him and 9 per cent couldn't make up their minds.
Both frontrunners are campaigning hard with just two days to go. Mr Key will return to the election trail in Dargaville this afternoon to boost his candidate's chances.
Mr Osborne's punishing schedule yesterday started in Dargaville, took in a public meeting in Kaikohe and the opening of Opua's marina extension before returning to Dargaville for a "shed meeting" with another minister, Nathan Guy.
Meanwhile Mr Peters' Force for the North bus tour rolled into Paihia, Russell and Whangaroa.
The difference between the candidates' meetings mirrored the poll.
Mr Peters was in his element in Paihia, enjoying himself as he cracked jokes, batted away critics and announced a new policy on sex offenders to a crowd of about 40 people.
Mr Osborne spoke to a dozen people who were almost outnumbered by media in Kaikohe's Senior Citizens Hall.
Mr Peters repeated his message that a "seismic shift" was needed among Northland voters, "so that those bureaucrats in Wellington, and their political masters, will never forget you again".
The fact National had signed a free trade agreement in Korea, then said it was for Northland and that "some guy called Winston Peters is going to strike a dagger through its heart" showed how desperate they were, he said.
Meanwhile, Mr Osborne said the NZ First leader could "promise the world" but could not deliver. If elected, he would actually be able to get things done for Northland.
Mr Osborne would not be drawn on whether Mr Sabin's resignation had affected National's support.