The calls came as it emerged the Paul Murray-led Blue Knights consortium have now backed away from their rescue bid after their original consortium partners, Ticketus, went behind their backs to try and negotiate a more lucrative deal for themselves with the rival Singaporean group.
The shock development now appears to put the Singapore offer, fronted by wealthy businessman Ng, in pole position to become the preferred bidder, although sources close to the bidding war say the deal between Ng and Ticketus has yet to be signed and sealed.
It is understood that the third bidder interested in Rangers, American millionaire Bill Miller, is now all but ruled out of contention by the club's administrators, Duff and Phelps.
The Blue Knights had agreed to pay Ticketus back £10m of their £27m four-year season ticket debt over nine years. There would be no interest due, no payments for the first two years, and no money owed in any season Rangers did not qualify for European football.
It is believed the Singapore consortium have offered to pay Ticketus back £14m over a shorter period, which has seen the London-based firm looking at jumping ship.
The three Rangers fans groups – the Rangers Supporters Trust, Association and Assembly – had also aligned themselves to the Blue Knights/Ticketus camp weeks ago and were shocked by last night's revelations.
Trust spokesman Mark Dingwall said: "We are surprised and disappointed if this is indeed the course of action Ticketus have decided to take.
"It would appear they are more interested in money going into their own coffers, than staying in Rangers. As supporters, given what has taken place in the past year, all we want is honesty and the truth.
"The Blue Knights said they would be up front and tell the fans what the deal was with Ticketus going forward; £10m back over a nine-year period was a figure we felt was manageable.
"I would urge the Singapore consortium and Ticketus to reveal the details of any arrangement they have in place so the fans know exactly where any future season ticket money is going.
"We continue to urge all parties to engage with the fans who are, after all, the biggest investors in the club."
There is anger within the Blue Knights group at the last gasp tactics deployed by Ticketus after weeks of negotiations.
A source said: "This may well offer a better deal for the creditors – but not for the club. It's more money that will need paid back to Ticketus, when every penny is going to be needed by the club."
The Blue Knights believed that with Ticketus on board, and crucially with their £27m debt out of the creditors' pot in the CVA that Rangers need agreed in order to come out of administration, they would be in a strong position to win the preferred bidder status.
However, when a final offer was put in to the administrators last Friday morning, the £500,000 deposit for exclusivity on the deal was left out by Ticketus without the knowledge of the Blue Knights.
Individual members of the Blue Knights then offered to put the deposit sum themselves to obtain preferred bidder status.
However, that could not go ahead when Ticketus stunned the Blue Knights by telling them they had been negotiating a more lucrative deal with the Ng consortium.
Their statement read: "On the evening of Thursday 12 April The Blue Knight Consortium was asked by Duff & Phelps to reconfirm its 'best and final' offer of 4 April. We recomfirmed our position and we believed that we would be awarded preferred bidder status on Friday morning.
"As part of the process of awarding exclusivity Duff & Phelps had requested a non-refundable deposit which the consortium had agreed to provide.
"During the course of Friday Ticketus decided that they were not prepared to provide this deposit. During the course of the weekend members of the consortium offered to put up the deposit subject to a small number of conditions which were broadly agreed with Duff & Phelps.
"During the course of the weekend we were made aware that Ticketus had been in discussions with the Singaporean consortium who, on Friday, had offered Ticketus a 'substantially' better deal to the one offered by us. We confirmed that we were not prepared to increase our offer to Ticketus.
"The consortium believes that the whole deal process has now become incredibly complex and it is critical that a preferred bidder is appointed this week.
"As a consequence, in the best interests of the Club, the consortium has decided to take a step back to enable Duff and Phelps, Ticketus and the Singaporeans to conclude a deal as quickly as possible.
"We stand ready to complete our offer of 4 April which included a deal in principle with Ticketus. We still believe that a partnership with Ticketus represents the best opportuntiy of the Club exiting administration via a CVA.
"We firmly believe that in the interests of the Club the whole process has to move forward as a matter of urgency. We are stepping back to assist with this."
Joint administrator David Whitehouse said he still hoped to name a preferred bidder this week, although the longer the saga goes on, the more fears of liquidation grow.
He said: "It is disappointing the Blue Knights are withdrawing at this stage, particularly in the view of the fact that last week it was made clear to them and Ticketus that their indicative bid placed them in a strong position.
WE were therefore surprised that their offer to pay an exclusivity fee was withdrawn.
"Although discussions over the exclusivity fee continued over the weekend, no agreement was reached.
"At all stages of the process, The Blue Knights/Ticketus bid has been given the most serious consideration by us as administrators, particularly due to the fact that it was being encouraged by supporters' groups. We are aware that Ticketus has also been, at their own instigation, in parallel discussion with one of the other bidders over the last few weeks and it remains to be seen whether these discussions will be taken forward.
"We can reassure supporters that we look forward to making an announcement on a preferred bidder later this week, assuming no further hurdles are placed in our path. While we as administrators have a statutory duty to look after the interests of creditors and keep the business going, it is of paramount importance that the bid which is taken forward is the best on offer for Rangers Football Club."