However, the couple say they won't be taking up any more space than Gibson already does in his one-bedroom unit, as they will be living as a married couple.
Gibson said they advised the council about Hira's intention to move in, because he was a decent tenant but was told that if she did move in, his tenancy would be terminated.
Council communications officer Kelvin Teixeira said the HDC must follow its policy that sets out criteria for offering pensioner housing.
"Pensioner housing in Horowhenua is clearly identified for people over 65 years old, or those over 60 who have a permanent disability and are in need of housing," he said.
"Mr Gibson has been made aware that any application that does not meet the criteria must be declined. This is only fair and reasonable to everyone, especially those who do meet the criteria and are currently on the waiting list for pensioner housing."
Gibson said he had met council chief executive David Clapperton to discuss the fact that their case might be a grey area, given they would not be taking up any space that someone else may be on a waiting list for.
He said Clapperton told him he would look into it as he didn't think it was council policy to block Hira from moving in with Gibson. But a follow-up phone call with the Clapperton's secretary stated that it was policy and Hira could not move in, or eviction was a possibility.
However, when the Horowhenua Chronicle spoke with Clapperton yesterday, he said he was looking into the situation.
"We do have a pretty defined criteria for occupants, but I've had a chat to them and there's a little bit of work I could do to see if there's a way forward, given the future," he said, referring to the housing's upcoming sale to the Sisters of Compassion, a Catholic charity and community housing provider.
Sisters of Compassion manager Gerard McGreevy said they didn't have exact rules to cover situations such as Gibson and Hira's, but that if the same circumstances occurred in the organisation's Hutt Valley pensioner housing, he "can't see that we'd have an issue with that".
The couple said they had been feeling upset and discriminated against, and had even contacted the local tenants' union. "They said they'd never heard of anything like it," Gibson said.
"We had hoped the wedding would be at the end of this month, but it's on hold because of all this."
Gibson said he was happy the housing was being taken over by the Sisters of Compassion, and hoped they would have good people skills, but was pleased to hear Clapperton would be looking into the issue personally.