The ACT Party is facing an election wipeout – with a new poll showing Epsom voters have been turned off by last week's tea party.

A Fairfax Media-Research Media International mini-poll of 200 eligible Epsom voters showed National's Paul Goldsmith easily winning the seat on 45.5 per cent.

ACT candidate John Banks trailed on 29.1 per cent, while Labour's David Parker had 14.6 per cent. The snap poll, taken on Tuesday, showed last Friday's meeting with National leader John Key shifted support away from Mr Banks.

Almost 30 per cent said they were now less likely to vote for him. Just under 23 per cent said Mr Key's public endorsement made it more likely they would favour Mr Banks. About 43 per cent said it made no difference. However, the poll also showed almost 40 per cent were undecided over the blue-ribbon seat, suggesting voters were waiting to see if National needed ACT as a support partner.

A former Auckland mayor, Mr Banks must win if ACT is to survive. Most polls have ACT's party vote at 1 per cent – well short of the 5 per cent threshold needed to return to Parliament. Last night, Mr Banks was unfazed, noting that ACT's internal polling showed similar numbers.

"I'm not surprised. Our polling has 45 [per cent] undecided. We've got a long way to go, a lot of people have got to make up their mind."

Mr Banks is gearing up for a big push in the electorate next week, enlisting 60 volunteers to help out as he campaigns.

Asked if his party's future was precarious, ACT leader Don Brash said: "Only time will tell, there are 10 days to go. I would have thought that after the prime minister made his views pretty clear, National Party supporters will, in due course, see the logic."

Mr Goldsmith, a former Auckland city councillor, could not be reached for comment.

His campaign – solely for the party vote – has been low-key.

Labour rival Mr Parker has joked he is "campaigning with a paper bag over his head".

Yesterday, Mr Goldsmith, who is likely to enter Parliament on the party list, was photographed removing unauthorised billboards advertising his candidacy.

In the poll, voters had a clear view of which party would get their vote – almost 61 per cent would go with National. Labour attracted a 17.1 per cent share and the Greens 15.6 per cent. Just 2.7 per cent would give their party vote to ACT – although this is more than double what other nationwide polls are registering.

Mr Goldsmith appeals to men and women equally, but Mr Banks is slightly more attractive to women than men.

Mr Parker believed a chunk of the undecided had made up their mind not to vote for Mr Banks.

"They won't say but they are going to vote National ... I'm not surprised, the whole thing is a circus." He said Mr Goldsmith was "hamstrung". "I would predict that he will be the first candidate for Epsom that says `please don't vote for me' but still gets elected."

The poll has a margin of error of 7 per cent.