The Government's agreed to add debt-to-income lending restrictions to the Reserve Bank's toolkit..

But, only on the condition it has minimal impact on first-home buyers.

The move would cap how much someone can borrow based on their income.

The Reserve Bank's been keen to add it for years -- but only now has the Government given the go ahead.

Finance Minister Grant Robertson's agreed after advice given last month -- on the condition any implementation avoids impacts on first-home buyers.

There's no immediate plan to use DTIs -- and it would only happen after a full public consultation.