Key Points:

United Future defector Gordon Copeland has infuriated political rivals and been ridiculed after giving his vote on legislation to the National Party, apparently with no strings attached.

Mr Copeland, who left United Future last month because he was unhappy with party leader Peter Dunne's support of anti-smacking legislation, said yesterday he had reached a deal with National over his vote.

He will continue to support Labour on confidence and money-supply issues, meaning the Government is not under threat.

But he will let National cast his vote whichever way it wants on other legislation.

That means that a day after he indicated he might support a compromise on a transtasman regulatory agency for medicines and therapeutic products, Mr Copeland's vote now looks more likely to go in the opposite direction.

Backers of the compromise solution were yesterday understood to be less than delighted with Mr Copeland's announcement, and Mr Dunne said his former colleague was deceptive and deluded.

Mr Copeland said that outside crucial confidence and money-supply votes, he wanted to be seen as the 49th member of the National Party caucus.

If National opposed the compromise being sought on the transtasman agency, his vote would be cast that way too, regardless of whether the compromise was what he had been seeking.

"It's part of the deal that I've agreed to with the National Party that I will give my proxy to them on all other legislation," Mr Copeland said.

Asked what he had been promised by National in return, Mr Copeland said, "Nothing of great substance".

"It would be fair to say that ... I was perhaps more anxious for this to happen than they were."

Mr Copeland said he was happy for National to decide how his vote would be cast, because with 48 MPs the party had a lot of experience.

"They won't vote against legislation unless they believe that a sizeable proportion of the voting public will be on their side of the issue," he said.

Asked if that meant he effectively would not be forming his own positions on legislation as an independent MP, he said, "That's pretty right".

Mr Copeland talked to Labour, United Future and National about his proxy vote before making his decision.

He said he approached National himself, and there had been some "interesting" negotiations along the way as other parties were "wooing" his vote.

Mr Copeland said he had received many supportive emails and letters since his break from United Future and was "completely focused" on setting up a new party with former MP Larry Baldock for the next election.

He also said that the new party, Future New Zealand, would not support a Labour-led government.

That comment led Mr Dunne to suggest his former colleague, who got into Parliament because of the United Future leader's victory in an electorate seat, was deluded.

"I think people will see that as a delusion, the assumption that lies behind it," Mr Dunne said.

"They will conclude that it's a bit ironic to be founding a party based on high principle when deception is your first major act."

Deputy Prime Minister Michael Cullen said he was disappointed with Mr Copeland's decision, but not overly concerned.

Mr Copeland's first move after his announcement yesterday was to try to secure support to amend the Government's intended appointments to the Abortion Supervisory Board.

But he did not get enough votes to get his change made.