The political and financial aftershocks of Manchester City’s guilty verdict in football’s biggest-ever financial fair play case are spreading well beyond the Premier League, with tax authorities, Westminster and Downing Street all now entangled in a row that shows no sign of settling before the club’s appeal deadline on Friday.

An independent commission this week found City guilty on all but one of 115 charges relating to breaches of Premier League financial regulations between the 2009-10 and 2017-18 seasons, concluding that the club had used “sham” sponsorship arrangements and disguised funding, backed by owners Abu Dhabi United Group (ADUG), to mask the true scale of its finances from regulators. City deny all wrongdoing and say the decision contains “clear material errors, of law, principle and fact” that render it “unsafe.”

Now the Treasury Committee has waded in. Its chair, Dame Meg Hillier, has written to JP Marks, permanent secretary at HM Revenue and Customs, asking whether the tax authority has sought an unredacted copy of the commission’s report and whether it is alive to the “public interest” in the case. Her intervention follows a report from Tax Policy Associates alleging City may have failed to pay as much as £12m in tax tied to a “sham” contract involving former manager Roberto Mancini — a liability that, with penalties, could reportedly balloon to £24m.

Hillier was careful to acknowledge the limits of what HMRC can say publicly, noting that “taxpayer confidentiality may inhibit what you can disclose,” but pressed for assurance that the department understands the stakes. The request centres partly on the commission’s finding that City “utilised devices” to “disguise the true extent of certain club liabilities” — language that has caught the eye of MPs well beyond football’s usual regulatory bodies.

City, meanwhile, are preparing a defence for their appeal that could reignite one of the most sensitive questions in modern football governance: where the line sits between a private football club and the state that surrounds it. According to reports first carried by the Daily Mail and the Times and corroborated by BBC Sport sources, City intend to argue that money which flowed into major sponsorship deals came directly from the Abu Dhabi government rather than from ADUG, the private investment vehicle owned by Sheikh Mansour. Premier League rules explicitly permit state bodies to sponsor clubs, meaning the distinction, if accepted, could undercut the commission’s central finding of a “disguised funding scheme” worth an alleged £830.69m.

The commission has already heard — and rejected — a version of this argument once. It described City’s prior explanation, that Abu Dhabi sponsors had simply sought and received government assistance to cover their own liabilities, as “untrue” and something the club had “concocted well after the event in an attempt to obscure and conceal the realities of the disguised funding scheme.” Whether a fresh appeal board reaches the same conclusion will likely determine not just City’s sporting punishment but the broader debate about ownership transparency across the league.

That debate has taken on an added edge given the position of City chairman Khaldoon Al Mubarak, who insists there is “irrefutable evidence” supporting the club’s case. Al Mubarak is listed as an Emirati diplomat on the UK government’s register of foreign representatives, a status that confers immunity from prosecution under criminal, civil and administrative law — a detail likely to fuel further questions about how closely the club’s leadership is bound to the Gulf state. Sheikh Mansour himself is a senior member of Abu Dhabi’s ruling family and brother to the UAE president, a lineage human rights campaigners have long cited in accusing the club’s ownership of using English football to “sportswash” the UAE’s international image.

Separately, City’s shirt sponsor Etihad Airways has said it is weighing legal action against the Premier League over the fallout from the ruling, adding a commercial dimension to a dispute that has already drawn in regulators, tax officials and now, improbably, the Prime Minister.

Andy Burnham found himself at the centre of a political storm of his own this week after telling the BBC he would be “really concerned” if City’s Abu Dhabi owners sold the club following the verdict, praising them as “a huge partner in the building of modern Manchester.” The Prime Minister went further, drawing a comparison to the disciplinary case against Everton — the club he has long supported — suggesting history might judge the City verdict as harshly as he believes it judged Everton’s.

The remarks prompted swift criticism, with shadow sports minister Louie French urging the government to “keep politics out of football.” Downing Street moved quickly to contain the row, with a spokesperson stressing on Thursday that “the initial judgement is serious and there can’t be any suggestion that anyone is above the rules,” while insisting the independent process “must be allowed to run its course and the outcome respected.” A spokesperson for Burnham similarly stressed the verdict was “serious” rather than retreating from the comparison entirely.

With City expected to formally lodge their appeal before Friday’s deadline, the case now sits at the intersection of sports governance, tax law and diplomatic politics — a combination that suggests the Premier League’s reckoning with its richest club is only just beginning, regardless of what a sanctions hearing eventually decides.