Christchurch Central MP Nicky Wagner is to be appointed as a Minister outside Cabinet.
Ms Wagner replaces Mauruice Williamson who resigned last week after it was revealed he had discussed a police investigation with a senior officer.
Ms Wagner will be Minister of Customs, Statistics, Associate Conservation, and Associate Canterbury Earthquake Recovery.
Nick Smith will take on the Building and Construction portfolio, and Michael Woodhouse will take on Land Information.
Ms Wagner will be sworn in on Wednesday.