Labour MP Louisa Wall is hoping the Prime Minister's near-endorsement of her bill to legalise same-sex marriage could give it the legs to pass into law.
Ms Wall's marriage equality bill, pulled from the ballot last Thursday, was given a significant boost yesterday when Mr Key hinted he would extend his support beyond the first hurdle.
Mr Key has previously said he would support the bill at the first reading, but said yesterday his conscience vote was unlikely to change if the bill progressed.
"You'd have to go through all the merits of the argument then see what people put up, but my view has been that if two gay people want to get married, I can't see that it would undermine my marriage to Bronagh, I just don't understand how that logic applies," he said in a radio interview.
"Let's go and have all the debates, I haven't spent a long time thinking about it. I'm giving myself a bit of room but in principle, I'm not opposed to it."