The Government has received the much-anticipated Tax Working Group report and says it will respond to its recommendations in two months' time. But the report won't be made public until later this month.
New tax policy is not expected to come into force until around April 2021, after the 2020 election.
Finance Minister Grant Robertson said that would give New Zealanders the chance to vote on any decisions made by the Government.
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The report is due to be released to the public on February 21 and the Government would then give an initial response.
Before then, it would be analysed by officials and discussed with coalition and confidence and supply partners. It would be presented to Cabinet on February 18.
Cuthbertson said that rushed policy design and implementation will lead to unclear legislation and undercut the certainty taxpayers require. He described it as "an accident waiting to happen."
"We urge Government to reconsider whether taking a fully enacted capital gains tax legislation on the election campaign trail is, in fact, going to produce the best policy outcomes.
"For voters to understand what's changing, setting out the detailed policy design should be sufficient. Deferring the enactment of legislation will provide the additional time needed to ensure the legislation is sound," Cuthbertson said.
"Our tax system is based on taxpayer trust. Certainty, or at least predictability, flows from coherent tax law and administration. When you rush complex legislation, mistakes and unintended consequences will inevitably result," he said.