National sources have said former prime minister and Luxon mentor Sir John Key has spoken to at least three MPs making the case for Luxon.
Two of these conversations were Key returning a call from MPs who had contacted him first, but one was Key proactively reaching out.
Sir John Key told the Herald he was not calling around MPs to lobby for Luxon, but had spoken to a few who had contacted him to ask about it.
He had also rung one MP himself.
Key has been making the case for a Luxon leadership, believing Luxon was the best person to stabilise the party, but Key would prefer Luxon and challenger Simon Bridges to strike a deal behind the scenes rather than watch the leadership go to a contest at National's caucus meeting on Tuesday.
Bridges is the only MP to openly contest the leadership, although Covid-19 spokesman Chris Bishop admitted to Newstalk ZB on Friday he was considering putting his hat in the ring too.
It is not clear what support Bishop's bid might have.
An MP told the Herald Bridges was hitting the phones on Saturday, trying to win over caucus colleagues.
Luxon himself is apparently not working the phones, leaving Key to make the case for him.
"He wants it given to him," the MP said, adding that if Bridges appeared to have momentum, then Luxon would withdraw rather than lose an open contest.
Multiple sources have said the race is "close", but the mood in the caucus is for a consensus decision rather than an open contest.
The vacancy follows former leader Judith Collins being deposed by a vote of no confidence in her leadership on Thursday.
National MPs have until Tuesday to make up their minds.
MPs spoken to by the Herald see Luxon as "a clean slate" with "reasonably high risk" as an unproven Parliamentarian versus Bridges who is proven, confident but potentially damaged goods.
The case made by the pro-Luxon supporters is that a Bridges leadership could be undermined by Collins, who has vowed to stay in Parliament.
