Rangers today took their battle against a 12-month transfer embargo to the law courts.
Administrators Duff and Phelps announced that legal proceedings had begun against the Scottish Football Association in the Court of Session in Edinburgh.
In a statement, joint-administrator Paul Clark said: "The club started proceedings at the Court of Session today in an attempt to challenge the imposition by an SFA judicial panel of a player signing embargo."
"The process will continue at the court on Tuesday and it is the club's position that the judicial panel did not have the powers to impose such a sanction.
"The club and the administrators are grateful for the support of the Rangers Fighting Fund on this matter."
The club's argument centres on the fact that the punishment, specifically a ban on registering players aged over 17, is not explicitly laid out in the SFA rules and so they claim it was not available to the panel.
However, the SFA articles of association include a clause that a judicial panel can implement any sanctions they deem appropriate.
Rangers last week lost an SFA appeal against the punishment, which was handed down over their failure to pay £13million in tax last season.
The disrepute charge was one of five offences Rangers were found guilty of in relation to their financial affairs and the appointment as chairman of Craig Whyte, who was deemed unfit for a role in football by an SFA-commissioned independent inquiry over his previous disqualification as a director.
The initial three-man judicial panel, which also fined Rangers a total of £160,000, was chaired by a QC and the appeal panel chairman was serving judge Lord Carloway.
The appeal verdict stated: "Although the appellate tribunal has listened carefully to the representations from Rangers FC about the practical effects of the additional sanction, it has concluded that this sanction was proportionate to the breach, dissuasive to others and effective in the context of serious misconduct, bringing the game into disrepute."
Charles Green, the former Sheffield United chief executive at the head of the consortium that has agreed to purchase the club, previously backed the administrators in their attempts to challenge the ban.
The club's challenge, led by Richard Keen QC, is being paid for by the Rangers Fans Fighting Fund, which was formed to enable supporters to help the club through administration.
Rangers fear the embargo will leave them without an experienced team next season as several of their leading players negotiated exit clauses when they agreed to temporary wage cuts.
This means they are free to leave for a specific cut-price fee from June 1, when their wages are due to revert to normal.
Green signed a contract putting his group in an exclusive position to buy the club almost two weeks ago but plans to send a Company Voluntary Arrangement proposal to creditors on Monday did not materialise and administrators revised their target to some time this week.
Creditors would have two weeks before voting on any offer and, if a CVA is approved, there is a 28-day cooling-off period before the club would be able to come out of administration.