Championship club Bolton have confirmed that they have been served with a winding-up petition by HM Revenue and Customs (HMRC) over an unpaid tax bill.
The club's financial problems have increased rapidly over recent weeks, and it was revealed that they had failed to pay their players for November.
HMRC has rejected requests from Bolton, who were relegated from the Premier League in 2012, for more time to conclude a sale of the club.
Bolton had hoped they could conclude a takeover this week after drafting in financial adviser Trevor Birch to help owner Eddie Davies -- who is willing to wipe out £185 million of loans owed to him -- sell the club.
However, with discussions still ongoing, HMRC has now acted to call in unpaid PAYE and VAT for the month of November.
That raises the possibility of administration for Bolton, who are at the foot of the table and would have their points total for the season wiped out if they were to incur the 12-point deduction that automatically entails.
A statement on the club's official website said: "Bolton Wanderers can confirm that the club has now received a winding-up petition from HMRC in respect of unpaid PAYE and VAT for the month of November.
"Despite requests from the club to HMRC to give it further time to either conclude a sale or raise additional funds, HMRC has proceeded with due process and duly served a petition."
Birch said: "Quite clearly, the club remains in a critical financial position.
"We will continue to try and finalise a sale or alternatively raise some short-term funds needed to give the club a breathing space and time in which to consider its options."