The average collectivist greens person does not want to increase immigration either because of greed or prejudice. However, a larger population will preserve the environment if a system of private property rights is maintained.
Legislation that reduces a landlord's right to raise rent or to evict tenants reduce supply and drives up rents anyway. Paul Keating deregulates the cost of home purchases while the Minster for Housing regulates rents. It will not work.