An Act candidate touted as a future leader has declared the party all but dead and represented by an "economically ignorant" John Banks who wants to "suck up" to National.
Stephen Whittington, 25, ran in Wellington Central and was seventh on the party list. Along with number five on the list, David Seymour, he was regarded as a future star.
On his Facebook page Mr Whittington called Mr Banks "economically ignorant and interventionist", in response to the Epsom MP's comments opening the door to Conservative Party leader Colin Craig.
He later said he believed Mr Banks was against asset sales, but Mr Banks said he supported them.
Mr Whittington said Act's liberal flame was dying.
"Banks' post-election comments [on Mr Craig] certainly clarify that there is no liberal future in the Act Party. Only if the board moves to significantly reduce his role in some way would anything else be feasible, and that seems unlikely and implausible."
Mr Banks declined to comment, but party president Chris Simmons said Mr Whittington was wrong.
"The bottom line is that the party has a lot of work to do. In Parliament we're represented by only one person, and John Banks signed up to represent Act and Act's principles and he's working really hard at exactly that."
He believed the party would survive.
"Will it be a liberal party? Yes, it will be. Will it be the liberal party that Stephen Whittington thought it would be? I'm not really sure about that."
Mr Whittington said Act needed a counterbalance to Mr Banks to maintain a consistent liberal message.