Portsmouth administrators have released a statement claiming that there is a "real possibility" that the Championship club will not be able to finish the season.
Joint administrator Trevor Birch has admitted that the former Premier League side are struggling to survive due to the unlikelihood of receiving further parachute payments.
A statement on the club's official website said: "Following our discussions with the Premier League and Football League over the past few days, it has emerged that Portsmouth Football Club is unlikely to receive any further parachute payments or other league funding.
"We had previously stated that there was a real danger of the club running out of cash before the end of the season. The risk of this happening increases substantially without the money from the football authorities. Unless something significant happens, there is a real possibility that we may not be able to fulfil the season's fixtures.
"One potential issue appears to come from the assignment of £2.2m of parachute payments that was made by the old company to a previous owner. We have instructed lawyers to challenge this, but the process may take time.
"The club is also still owed nearly £300,000 by the CSI administrators and their lawyers, who are withholding the funds as payment for their work in applying to court for administration. PKF is talking to its lawyers to see if this money can be returned to the club.
"Despite the tremendous support that we've received from everyone involved with Portsmouth Football Club, it seems that the club isn't getting any of the breaks that it needs. The more we uncover, the worse the picture appears to get.
"The only consolation I can give supporters, staff and players at the moment is that my PKF colleagues and I have not given up hope and will continue to do all we can to save the club. But the clock is ticking."
Portsmouth entered administration for the second time in as many years earlier this month.
