Portsmouth have been told they face the threat of explusion from the Football League if the Pompey Supporters Trust (PST) fail in their bid to buy the League One club.
Portsmouth's administrators, PKF, on Thursday revealed they had received a new offer from former Football League chairman Keith Harris which would rival the PST's bid.
But the Football League reacted to that news by releasing a statement making it clear they would not consider any new bids for the 2008 FA Cup winners.
As a result, Portsmouth, relegated from the Premier League in 2010, now face being kicked out of the professional game if the PST can't complete their takeover, as Football League rules don't allow clubs to be in administration for two successive seasons.
"The League had previously been informed by PKF that its preferred bid for the club was from the Pompey Supporters Trust (PST) and all parties have been focused on a successful transfer of share to that consortium," a statement read.
"Given that the Football League's Insolvency Policy prohibits a club from beginning two consecutive seasons in administration, the board took the view that any change of preferred bidder at such a late stage would only create further uncertainty and was not in the wider interests of the League and its member clubs.
"Therefore, the League has informed the administrator that it will not currently consider transferring the club's share in The Football League to a new bidder.
"This means that in the event that the PST bid does not succeed and Portsmouth do not exit administration before the end of the current playing season, the club will lose its membership of The Football League."
The PST are the preferred bidder of PKF but their proposal hinges on buying the club's Fratton Park ground, which is still controlled by former Portsmouth owner Balram Chainrai.
PKF are seeking permission to sell the ground and are due in court with Chainrai's company Portpin next Thursday.
Pompey have been in administration since February last year and will be deducted 10 points if and when they exit.
They are currently second from bottom in League One after losing their last eight matches.