National says independent legal advice tells them a tax on foreigners buying houses will work. 

The party's unveiled its $14.6 billion tax policy, which includes shifting income brackets and expanding tax credits. 

It would pay for it, in part, by ending the ban on foreign buyers - for homes worth more than $2 million and taxing them 15 percent.  

National finance spokesperson Nicola Willis told Mike Hosking they can do it while complying with the free trade and tax agreements. 

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