Chairman David Cardoza plans to sell the club to ex-Oxford United chairman Kelvin Thomas.
But Mr Thomas warned it is too early to know if he can resolve "the very complicated situation of outstanding debt" to enable the purchase.
The club owes Northampton Borough Council more than £10m.
Mr Thomas said: "We have found a very complicated situation with outstanding debt, parcels of land with different leases, various creditors and winding-up petitions.
"At this stage it is still too early to know whether we will be able to properly resolve these issues to allow a sensible deal to proceed."
Northampton Town chief executive James Whiting had previously said the sale would only go through if Mr Thomas was able to do a deal with the council over a £10.25m loan.
The loan was to have been used to redevelop the club's Sixfields ground, including the building of the new East Stand along with a hotel and conference centre - none of which have been completed.
A winding-up petition has been sought by HM Revenue & Customs, to whom Mr Whiting said the club owed £166,000.
Mr Thomas said that he had "agreed a deal in principal for the purchase... subject to the usual legal and financial due diligence".
He added: "Our interest is to take the football club forward and are prepared to invest significant funds to immediately stabilise the club off the pitch, support the team on the pitch and complete the East Stand."
Manager Chris Wilder said he would relish the prospect of working with Mr Thomas once again.
A "sensible deal" to buy Northampton Town may not be possible, according to the man who wants to take control of the football club.