King said Murrie was "in immense pain" and needed the cannabis to sleep, but was caught by a rigid policy.
"Housing NZ has a zero-tolerance policy to drugs, any drugs," King said. "This is one of the first cases they have ever seen sense."
Housing NZ issued the eviction notice last year after police charged Murrie with cultivating cannabis. The case is still before the District Court.
King said he took her case to several Opposition MPs without success, then finally walked into the Te Atatu office of the new Associate Social Housing Minister Alfred Ngaro last week. Ngaro was out, but his secretary listened.
"She was really good, she kicked ass," King said. "She cares."
Ngaro's secretary referred him to Amy Adams, who picked up the senior Social Housing and Housing NZ portfolios after former Housing NZ Minister Bill English became Prime Minister last month. King rang Adams' Beehive office and spoke to her Housing NZ secretary for about half an hour.
"They seem to be listening," he said. "I think this could be a change in their thinking."
Adams told the Herald that the Government had been funding a $6 million scheme since last July to help community organisations working with social housing tenants who are at risk of eviction.
"I expect Housing NZ to work with tenants to help them sustain their tenancy wherever possible," she said.
A Housing NZ spokesman said the agency still did not tolerate illegal activity, but took account of "personal matters" in Murrie's case.
"Our policy is that we don't allow illegal activity in our properties and where it occurs we'll look to end the tenancy," he said.
"In this case, we're happy with the outcome of the meeting our regional manager held with our tenant, Ms Murrie. She is a long-term tenant with a good record as a tenant, and we've taken into account some personal matters relating to her situation.
"She has made an assurance that she will not repeat the actions that nearly resulted in the end of her tenancy and has agreed to being monitored every three months to ensure this is the case."