The hearing began at around 11am but was immediately delayed as the revenue submitted extra documents to the judge, Mr Justice Mann. The case opened at approximately 12:30pm with HMRC's QC, Gregory Mitchell, declaring that the case "not about precise figures, it's about principle."
Mr Mitchell then told the court that Pompey owe HMRC £30 million, a figure that dates back to the 2006/2007 tax year and onwards where the club did hasn't paid the PAYE that it owes.
"What has happened is for some years the club has entered into sham agreements under which players were being paid in respect of image rights when in fact there was no commercial basis for it. It was a sham. It was a way in which the club could pay the money into a tax haven."
The case continued and broke for lunch before restarting at 2pm, when Andrew Andronikou made his appearance as the legal arguements continued.
Mitchell used the word "sham" again to describe how Pompey allegedly avoided tax by paying money into players' employment benefit trusts which were disguised salary payments in which PAYE was due.
More complicated legal rambling ensued before Mr Mann asked Mr Mitchell basically clarify why HMRC has brought this case upon Portsmouth FC and the focus of the debate switched from Pompey's "tax evasion" to the difference of the rules of association from the Premier League to the Football League.
The day ended with a study into what happens when a club becomes insolvent, with HMRC using Wimbledon as their case study.
Proceedings will begin again at 10:30am tomorrow, where Pompey will begin their defence against HMRC's appeal before a verdict is (hopefully) reached on Thursday.
The general consensus from the first day's events is that the judge wasn't too impressed with HMRC's case that they put forward, hence asking for clarity.
It'll be interesting to see how Pompey's lawyers will react to HMRC's allegations of avoiding tax and how the case of Portsmouth FC is vastly different to that of Wimbledon FC's.
I'm a little more optimistic about HMRC's appeal being thrown out, but there is still a long way to go yet and I expect more revelations tomorrow.