A former Labour leader says there'll be a sense a relief among many to see a new capital gains tax policy.

Labour's announced the policy for next year's election campaign, targeting commercial and investment properties, but not family homes. 

The revenue would go into health, creating a Medicard scheme providing free GP visits.

Phil Goff told Ryan Bridge the OECD has been calling out New Zealand for being the only country in the western world not to have the tax.

He says Labour's putting it in place for the sake of fairness and making sure investment decisions aren't distorted by being the odd one out.