There's belief the Government may be preparing the groundwork for a capital gains tax - if elected for another term.

Revenue Minister, David Parker, has launched the Tax Principles Bill, which will likely include things like fairness and effectiveness.

He says Labour's committed to not passing any new taxes this term, but is coy on what tax policy the party will run at next year's election.

PWC tax partner Geof Nightingale told Mike Hosking Parker was at great pains to rule out again no capital gains or wealth taxes under this Government.

However, he says it's clear he's setting up the narrative for a future political mandate for more capital taxes.

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