The National Party's finance spokesperson says the new Labour-led coalition government needs to front up on how much its policies will cost the country.
Finance Minister Grant Robertson told TV3's The Nation programme that Labour had only limited resources to have its policies costed because it had been in opposition.
Mr Robertson said the Labour-led government would now work with the public service to refine its estimates.
But National's finance spokesperson, Steven Joyce, said all parties in post-election coalition negotiations had access to the public service to get their policies costed, and he said Mr Robertson needed to stop making excuses.
"They can have Treasury information, they can have access to costings, and that's all been set up to make sure that parties don't make commitments that they can't then fund.
"So he's actually had all those access to officials and to turn around this weekend and say that he can't release the costing details because he hasn't had access to people who know what they're doing is just simply wrong."
Steven Joyce attacked Labour over its fiscal plan during the election, claiming it had an $11.7 billion hole, but that claim was widely discredited by economists.