Former National and Act Party leader Don Brash says Winston Peters is the best chance of "ending National's race-based policies".
Brash is a spokesman for a lobby group, Hobson's Pledge Trust, that wants to end what it calls "Maori separatism" by abolishing the Maori seats and remove all references in law and policy to Treaty "partnership" and "principles".
With just weeks until the election he has written an article for Elocal magazine, titled, "Use your vote to end National's race-based policies".
He concludes National has deceived its supporters and, in coalition with the Maori Party, gone "seriously off the rails in this area", listing examples such as the ratification of the UN Declaration on the Rights of Indigenous People.
Brash notes the Act Party as having a strong commitment to "one law for all" but says leader David Seymour, "gives the impression that this is not a policy priority for him".
On New Zealand First, Brash tells readers it is the party that has consistently called for a "colour-blind" state, and Peters this year announced policy to hold a binding referendum on whether the Maori seats should continue.
He questions whether Peters can be trusted, given he didn't use his bargaining power to move New Zealand to a "colour-blind society" in 1996 or 2005.
"Nobody knows for certain how Mr Peters will use his bargaining power ... [but] on balance, I think NZ First is the best chance we've got of moving New Zealand to a society where ancestry is absolutely irrelevant to our legal rights," Brash wrote.
He told the Herald that comment did not amount to a specific endorsement.
"We mention the fact that both Act and New Zealand First are saying things that are consistent with what Hobson's Pledge has been arguing for."
Brash said he was aware that under the Electoral Act his group could not specifically tell New Zealanders to vote for a party or candidate, without their approval.
He would not say how he planned to vote, but conceded it was something of a surprise to be praising Peters' stance given their opposition during his time in politics.
"It is [a surprise]. Having said that, on this particular issue New Zealand First has been consistent for a long time."
Peters has been approached for comment.
Brash has previously indicated support for Peters, last year saying, "I disagree with Winston on monetary policy, on the TPPA, a whole range of issues. But on this issue, he's absolutely right."
In April last year Brash submitted against proposed Resource Management Act (RMA) changes to the way iwi are consulted in the resource consent process. Peters had offered to support broader RMA reforms in exchange for removing any iwi-specific provisions.
Brash told a Parliamentary committee it was "incomprehensible" that Peters' offer was not taken up. Peters then sought permission for Brash to have his speaking time limit extended. That motion was denied, but the two men later continued their conversation over a coffee on Lambton Quay.
In the Elocal article, Brash wrote he hadn't met Peters since that meeting, which he said had been suggested by Peters.
"I said, 'you know Winston, this racial preference thing is the most important issue facing the Government right now'," Brash wrote.
"He corrected me: 'No,' he said. 'It's the most important issue facing the country right now.' I believe he meant it."
Asked how he thought the election could turn out, Brash told the Herald he was like most others in picking the most likely outcome was for Peters to hold the balance of power.
"I can't see it likely that either National or Labour will be able to govern without New Zealand First.