Simon Bridges appears to already be at odds with his finance and housing spokeswomen.
The new National leader revealed his reshuffled shadow Cabinet on Sunday, and immediately afterwards said it was "pleasing" to see the Government investigating new ways of funding infrastructure.
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Finance Minister Grant Robertson is looking into a land value capture tax, which would generate income for the Government by taxing those placed to benefit from new infrastructure the most.
"If we are going to make big investments in things like [Auckland's City] Rail Link, and a series of different rail links, people will benefit from that," he told the Auckland Chamber of Commerce-Massey University annual finance lunch on Friday.
"How do we capture the value of that, and use that to fund the development?"
Mr Bridges welcomed the Government's move.
"I think it's good. I think it's pleasing to hear from Grant Robertson today that finally he has come round to the need for innovation in this area. This is like so many areas where we I think did quite a bit, we were moving in that direction, I was certainly excited about doing more."
But his new finance spokeswoman, Amy Adams, has rubbished the idea.
"Another day, another new tax being proposed by the coalition Government," she wrote on Twitter. "Yet another attempt from Grant Robertson to make everyone else pay for all his promises."
Judith Collins, who was promoted to number four in the National list, also got stuck in.
"Here we go! Tax, tax, tax. Is NZ First going to support this envy tax?" she wrote.
Mr Bridges says their point was the Government doesn't have enough money to pay for it.
"The new Government knows it hasn't got the money to do the infrastructure, and they're looking for other ways - furiously - to do it," he said.
"I think it is good news that he has coming to realisation that he doesn't have enough money for the infrastructure that needs to be built in New Zealand, and some of these things such as value capture - I think there is a lot of detail that needs to be worked through - PPPs, and other private sector initiatives, can play a real role."
The Productivity Commission suggested the tax in a report last year. One way it could work is taxing the capital gains on property caused by the installation of new infrastructure, which would otherwise be paid for by every taxpayer.
Mr Bridges appeared on The AM Show on Monday morning, saying he wasn't "at odds" with Ms Collins and Ms Adams, saying the former was "fundamentally right".
"You should always be careful about taxes. What worries me with this Government is they'll put new taxes on and won't take other ones off."
But he continued to support looking into land taxes.
" I think the idea has some merit. When you're building a really big new rail line or something and there's people that benefit from that and they're getting a lot of uplift in their property prices, if that's what's needed to get it done, it can be entertained."