Christine Rankin has resigned as chief executive of the Conservative Party, saying yesterday's media conference held by former leader Colin Craig was the last straw.
Ms Rankin said Mr Craig set himself up as squeaky clean in a party with strong moral values and she was embarrassed by his conduct.
"I've just had enough", she said
"No-one could watch that terrible, terrible press conference yesterday and believe no action should have been taken. I have given advice, I have begged for something to happen and it hasn't and I just don't want any more."
She said she orginally resigned on Saturday but rescinded that resignation after several requests for her to stay so could continue to contribute in the days following Mr Craig standing down as leader.
"But really the whole thing is a train wreck and I need to walk away from it - I should have walked away on Saturday."
Ms Rankin said she really had no idea whether the party still had a future.
"People want to see decisive, firm action, we set ourselves up as a particular kind of political party, with values and morals and a very strong code of conduct, and that has been breached in every way - and still we don't act."
She said everything could be laid at the feet of Mr Craig.
'And he's making it worse with every action and every comment he makes."
Ms Rankin's resignation takes effect immediately.
Meanwhile Prime Minister John Key has said the National Party could benefit from the controversy surrounding Mr Craig and his party.
Mr Craig, who resigned as leader last Friday, said he hoped a confidentiality agreement could be lifted so he and his former press secretary Rachel MacGregor were free to speak publicly.
He has said some inappropriate conduct had occurred between himself and Ms MacGregor, but rejected any suggestion of sexual harassment.
In the past few days Mr Craig has been openly criticised by party executives, who said he had no future with the party.
Before last year's election, Mr Key ruled out an electorate deal with the Conservatives, to help them enter Parliament.
At Parliament he was asked whether that ended up being a good decision.
"Well look under MMP, governments have to put together coalitions, that's the reality under the system we have, so we work with all the different political parties and things that come along the way."
But he said National may well pick up some votes from disillusioned Conservative supporters.
"I would have thought that vote would come back to National 'cos it's more likely to be aligned with us but not necessarily guaranteed, I mean we've seen our numbers just very slightly higher than election day and Conservatives slightly lower so that's typical at this time of the cycle."