National list MP Richard Worth has accused Rodney Hide of "hoodwinking" Epsom voters by saying Act would go into coalition with Labour if it supported significant tax cuts.
But Mr Hide, the Epsom MP who said before last year's election that a vote for Act was a vote for a
National-led government, has rejected the claims.
He says National has done a u-turn on tax cuts, which entitled him to reconsider his position.
Mr Hide last week accused National of being no different to Labour, after National leader Don Brash said the party could not guarantee immediate personal tax cuts if it won office.
Mr Hide then raised the prospect of a coalition with Labour if it would commit to sizeable tax cuts.
Mr Worth, who lost the Epsom seat to Mr Hide, said National voters in Epsom had been hoodwinked by Mr Hide on at least two significant counts.
One was his claim that if they voted for him, it would put the Act team back into Parliament.
That had not happened because Act's party vote was too low.
"The second thing is that I'm sure Epsom voters didn't vote for Mr Hide on the basis that he'd take the Act Party into a possible coalition with Labour."
