Former Act leader Don Brash made an approach to Act president John Thompson recently to ask whether National's Pakuranga MP Maurice Williamson could join the party, it has been revealed.
Act leader David Seymour said the board had unanimously rejected any such notion. He also said he believed the approach by Dr Brash would have been authorised by Mr Williamson.
Mr Williamson was forced to resign as minister in May last year when New Zealand Herald investigations editor Jared Savage revealed Mr Williamson had contacted a high ranking police officer about domestic charges against a wealthy businessman with close ties to him.
Mr Seymour said taking someone into the party because they were having problems with their own party was the worst possible reason for getting a new MP.
"Of course I want to grow the Act caucus - I think about it every day - but I also know that the only way to authentically do it is to create a product people want to vote for and get more people to vote for Act.
"That's my mission. While it is nowhere near mission accomplished, I think we have been making reasonable progress since the election making ourselves look respectable.
"As soon as you try and start creating an amalgam of MPs from different parties, playing games, waka jumping and so on, you are no longer focused on the voter; you are focused on yourselves and that's not what I want Act to be.
"It is what it is: crazy old uncle approaches the president and says, 'What about this?' We said 'No, we are not interested."'
Mr Seymour believed Dr Brash would not have made the approach off his own bat.
"Don is many things but he generally acts very sincerely."
On right wing of party
Maurice Williamson was first elected to Pakuranga in 1987 and has always been considered on the right wing of the party, so much so that he considered joining Act for the 1996 election, the first under MMP when Act was first elected to Parliament with Richard Prebble as leader.
He was suspended from the caucus after the 2012 election for being openly disloyal to then leader Bill English but was brought back into the fold when Dr Brash become leader in 2003.
Dr Brash told the New Zealand Herald that he would not make any comment at all about the approach including whether it was made on behalf on Mr Williamson. He said he was no longer an office holder in the Act Party.
When it was suggested that making no comment could bring Mr Williamson into disrepute with his own party, he still chose to say nothing.
However assuming the approach was made on behalf of Mr Williamson, it suggests that Mr Williamson could leave National sooner than the next election, triggering a byelection.
Prime Minister John Key will not comment on the issue until his post-Cabinet press conference this afternoon, but a spokeswoman said "the view is that he is still a dedicated member of the caucus and there is no concern".
