Frustration from David Seymour, with talk of extending the bright line test.

Finance Minister Grant Robertson has asked Treasury for advice on extending the test.

It means people need to pay income tax if they sell a second property, that's owned for less than five years.

The test was introduced by National in 2015, and in 2018, Labour extended the test from two years to five.

Seymour told Mike Hosking when you introduce a new tax, they are like acorns - and they grow.

"The National Party planted this one, saying it would only be two years, now the test is at five years, and  it's likely to become ten."

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