SPARE a thought for the unloved and forgotten 10,000lb gorilla in the room.

Remember those straightforward, uncomplicated days when the Rangers story seemed to be all about "the big tax case"?

HMRC had descended on Rangers like the hounds of hell, chasing them for tens of millions of taxes allegedly due for a decade of hosing money at players via Employee Benefit Trusts. It all seemed so black-and-white back then: Rangers win the case, everything hunky-dory; Rangers lose the case, they hurtle towards the abyss.

It turned out that there wasn't any need to wait: they were in administration long before the verdict. The tailspin of deceit under Craig Whyte has been enough to bring Rangers to the brink of collapse and – incredibly – dilute the significance of what happens with the big tax case.

Even yesterday, we had Dave King, the club's second largest shareholder, claiming he has a verbal agreement to buy Whyte's shares, as if that even matters. Yet, the sideshow has only diluted not removed the issue. Those who dismiss the eventual outcome as a comparative red herring overlook a significant point. Even if it is no longer central to determining how the club emerges from its financial chaos, a negative ruling would have an enormously damaging and scarring effect on an already beleaguered club.

To recap: this slow, laborious, labyrinthine, complex and tediously dull investigation is close to a verdict. HMRC accused Rangers of massive tax underpayments on money given to employees between 2000/01 and 2009/10. Rangers appealed against the bill and the case has trundled on through First Tier Tax Tribunal hearings in October 2010, April, May and November 2011, and January this year. The disputed underpayment is around £24m but Rangers' liabilities could be far, far higher. "The total amount determined as due by HMRC in respect of this case is in the region of £75m, including interest and penalties," said administrators Duff & Phelps in their report to creditors on April 5. Or to put it another way, as former chairman Alastair Johnston did 14 months ago: "There's a 10,000lb gorilla in the room and you don't know what its appetite is."

The tribunal will decide whether or not to uphold Rangers' appeal and, therefore, the extent of tax, interest and penalties to be paid. Speculation on the amounts, and on HMRC's willingness to "do deals" on the interest and penalties, varies. Once the decision is reached, a judge signs it and the outcome is released to the parties within five days (and to others within the next 10 days). According to HM Courts and Tribunals Service website, decisions "can typically be about one or two months after the last day of hearing".

Not this time. The last evidence on Rangers was heard on January 18, so that's now four months and counting. When is it due? No-one knows. It's been coming "any day now" for weeks.

The argument that the big tax case has lost much of its relevance centres on the point that Rangers can only pay what they can pay. If Charles Green's consortium has only £8.5m for the creditors' pot then the tax bill may as well be £1bn because HMRC would still only get its share of that £8.5m. Of course, the more HMRC is owed, the less of a pence-in-the-pound return it would get from a CVA or moving for a winding-up order on Rangers.

Losing out on even more money could affect HMRC's attitude towards Rangers and towards accepting a CVA (supposing it has any inclination to do so in the first place). But the key point remains: Rangers under Green or anyone else can only pay what they can pay.

Where the outcome of the big tax case remains hugely important to Rangers is in relation to the damage it could do to their tattered reputation. There is a whole arsenal of accusations ready to come their way – years of financial doping – and the floodgates will open if they lose the case. They are already being accused of it by rival fans but, so far, it has not been proven.

Saying that others also used EBTs, or that he was advised that they were perfectly legal and commonplace, isn't going to sound like much of a defence for Sir David Murray if the case is lost. He took them down the EBT route and it has looked like a ruinous decision. Even if they win the appeal, the club has operated in the shadow of this case for two years and it scared off buyers.

Right now Rangers' sins relate only to a year of Whyte's ownership, making signings and improved contract offers to help them finish high up the league with £9m which should have gone to the taxman. If it is extended to a decade of underpayments under Murray, while trophies landed at Ibrox, the stigma will be impossible to remove.

Whyte has been flayed, but the coming days and weeks will determine how far the heat will be turned up on his predecessor. The SPL investigation continues into accusations of undisclosed payments to players on his watch, and Wednesday's Panorama documentary, "Rangers – The Men Who Sold the Jerseys", could be excruciating for him.

It claims to have seen dozens of emails, letters and documents which reveal much about Rangers, EBTs, and what happened when the club was passed from Murray to Whyte. The title alone suggests the Rangers drama is about to take another twist.