(CNN) -- New doubts have arisen over the future of Portsmouth after the struggling English Premier League club's administrator announced that Britain's tax department has mounted another legal challenge.
Portsmouth's existence had appeared to be safeguarded when owner Balram Chainrai put the 112-year-old outfit into administration last Friday to avoid a winding-up order in court.
That hearing had been delayed until Monday as Her Majesty's Revenue and Customs (HMRC) allowed Portsmouth more time to provide financial information, having been accused of owing nearly $12 million in taxes.
HMRC has now challenged Portsmouth's bid to stave off liquidation, administrator Andrew Andronikou said, and the club must face the High Court after all on Tuesday.
"We're having to go to court to show that the debenture is valid," he told the UK Press Association on Monday. "I don't understand the exact reason why this is, we're just following normal protocol. We're not unduly worried.
"It's not standard procedure but I'd imagine that HMRC are basically crossing their Is and dotting their Ts. We're expecting the administration to proceed as it was."
Chainrai had been in talks with potential new owners last week, but could not clinch a satisfactory deal for the club, which has debts of around $100 million.
Portsmouth have had four owners this season and are rock-bottom of the table.
Moving into administration will cost manager Avram Grant's team a nine-point penalty, making relegation to the second division an inevitability despite Saturday's morale-boosting 2-1 win at Burnley.