The council is holding back on its £9million loan that would go towards the £12million needed for the club to buy the ground, citing unacceptable risk.
The England and Wales Cricket Board (ECB) want the ownership settled by December 31, before they confirm the 15-year staging agreement for international games.
The club said it remained confident of tieing up the deal, but may be forced to ask the ECB for an extension to the purchase deadline if nothing is agreed soon.
It issued a statement saying "a loan will not be granted until final agreement on outstanding matters of detail has been reached between The Yorkshire County Cricket Club and [the council]."
It went on: "Since we have already reached agreement on all matters of principle, the club believes that the remaining points of detail can be resolved quickly and without difficulty."
Yorkshire also needs the approval of members at a Christmas Eve meeting to a change in its constitution that raises its borrowing capacity from £10million to £25million.
