The unidentified woman, a member of the Labour Party, wants to meet Mr Key to verify her version of events.
She has said that between November and February Dr Worth sent dozens of text messages and called her numerous times, and that some of the calls were sexually explicit and vulgar.
She has also said Dr Worth offered her jobs in his ministerial capacity.
Labour leader Phil Goff told Mr Key about the texts and calls early last month.
When Mr Key's office asked Dr Worth about them he denied the woman's version and threatened to sue Mr Goff if the information became public.
Mr Key accepted Dr Worth's denial, and now Mr Goff is trying to arrange a meeting so the woman can prove her credibility.
But Mr Key's office says she must first meet chief of staff Wayne Eagleson to prove she has the text messages, and then meet Mr Key.
A spokesman for Mr Goff said today Mr Eagleson spoke to the woman by phone on Friday and it was up to Mr Key to agree to a time and place.
But a spokesman for Mr Key said nothing had changed and Mr Eagleson had not been able to confirm the existence of the text messages.
Another woman has laid an unrelated complaint against Dr Worth with the police.
The Korean businesswoman has been reported as saying he invited her to a function in Wellington, arranged hotel accommodation for her and went to the room with her where "a sexual encounter" took place.
It was that complaint that led to Dr Worth's resignation last week but no details were known.
Dr Worth issued a statement last Thursday saying he was innocent of any crime and would vigorously defend himself against any accusations that he had broken the law.
The National Party's board met this morning and Mr Key updated members on the situation surrounding Dr Worth.
Mr Key's spokesman said no decisions had been made by the board.
Today, the Sunday News quoted Dr Worth's 28-year-old daughter Virginia as saying she stood by her father.
"I am 100 percent confident and sure that everything is going to work out perfectly," she said.
"I'm very proud of my father and he has been the most amazing and devoted parent anyone could wish for."
