Newcastle owner Mike Ashley has asked Rangers to pay back the £5m loan he gave the club in January.
Ashley owns 9% of the the Glasgow club, but has lost his influence on the Rangers board after Dave King took control of the club after a club EGM which saw the old board removed.
Derek Llambias, a former Newcastle managing director, took charge in December and appointed former Sports Direct executive Barry Leach as finance director, who had both previously worked for Ashley.
If the loan is paid back, the club will regain security over their branding, the Murray Park training ground and the club's retail rights, which were all handed over to Ashley's Sports Direct company as part of the loan agreement.
Ashley also wants to know why the club are not currently listed on the Alternative Stock Exchange (AIM), which has been the case since King took over and the club's nominated advisor WH Ireland stepped down, with no replacement yet appointed.
Ashley's involvement in the club was strengthened by an initial £2m loan, which was followed by the £10m loan in January, although only half of that was made available to the club immediately.
He also oversaw the loan signings of several Newcastle players to Rangers, as the club looked to complete their return to the top flight of Scottish football for the first time since being demoted to the bottom tier in 2012.