In a hearing at Stratford District Council on Monday, Tag Oil said it would consider pulling out of a proposed well site off Cross Rd near the town if it were forced to pay up to $1 million for a road upgrade before drilling began.
The figure was disputed by council officers who priced the required works at $380,000.
The application for the well site is being decided by a commisioner, Greg Carlyon, who gave Tag Oil and the council until the end of the week to identify the reasons for the vastly different costs and reach an agreement.
Failing this, he would issue a ruling.
The council had recommended a full road upgrade, which Tag Oil's New Zealand manager Randy Toone described as being "overkill".