EARLY on the morning of July 6th reporters began to assemble their tripods outside Avenfield House, a posh apartment block on London’s Park Lane. The air of wealthy anonymity that hangs around the red-stone building belies its notoriety; in Pakistan, there are few addresses more famous. The assembled hacks were hoping to catch sight of the alleged owner of flats 16, 16a, 17 and 17a: Pakistan’s former prime minister, Nawaz Sharif.

The four apartments are thought to have been knocked into one, and Mr Sharif is thought to be staying inside it. But it was from his son's nearby office that he gave his response to the verdict that Pakistan’s National Accountability Bureau (NAB), an anti-graft court, delivered later in the day, as to whether Mr Sharif and his family paid for the property with money that they had not properly disclosed to the Pakistani authorities. The NAB—pronounced “nab”—found Mr Sharif guilty just 19 days before a general election in which his party is fighting to remain in government. That leaves the 68-year-old, thrice-ousted prime minister with a very difficult decision to make.

The Panama Papers, a trove of documents leaked from a fancy law firm in 2016, suggested that Mr Sharif’s family owned the flats, which would imply that that they had income that they had not declared to the relevant authorities in Pakistan. Mr Sharif’s lawyers claimed that a Qatari investment fund had transferred the property to his children in 2006 to pay back a debt owed to his father, Mian Muhammad Sharif. The letter he proffered testifying to the deal, from a shy Qatari prince, was derided as a “joke” by Imran Khan, the leader of Pakistan’s main opposition party, the Pakistan Tehreek-e-Insaf (PTI). The NAB seems to agree.

Nevertheless, the NAB verdict strikes harder than Mr Sharif would have hoped. The ten-year prison sentence and £8m ($10.6m) fine he received raised few eyebrows. But the 7-year sentence given to his daughter and presumed political heir, Maryam (who must also pay a £2m fine) was “unexpectedly harsh”, says Zahid Hussain, a columnist. That she can no longer contest the vote on July 25th may mean that control of the party shifts towards Shahbaz, Mr Sharif’s brother and the chief minister of Pakistan’s most populous province, Punjab, with whom he has a somewhat testy relationship.

Mr Sharif is expected to appeal, focusing largely on procedural anomalies. His lawyer, Khawaja Haris, briefly quit the case, saying that the arbitrary rush to conclude the trial—handily, for Mr Sharif’s enemies, just before the election—was undermining its integrity. Suspicions that the die was cast against Mr Sharif from the beginning were not allayed by the details of the judgment, which relied heavily on the NAB’s unusual rules, in which a defendant is assumed guilty unless proven otherwise. “It was difficult to establish” ownership of the flats, the 174-page document admitted.

Mr Sharif argues that Pakistan’s judiciary is working in tandem with the army to remove him from the political stage. The NAB has become “a puppet of the establishment”, says one lawyer, who did not want to be quoted by name. The bureau’s chairman drew ridicule during Mr Sharif’s trial by launching an investigation into whether the ex-PM had laundered almost $5bn through India as prime minister: the case appeared to rest on a wildly erroneous newspaper article. At any rate, the NAB, like the rest of the Pakistani judicial system, has relentlessly focused on the PML-N. It arrested Mr Sharif’s private secretary this week (in order to “pull out each of his fingernails to compromise Mr Sharif”, says the shy lawyer), and earlier this month collared a PML-N candidate just hours after he announced he would contest the elections against Chaudhry Nisar Ali Khan, a former top lieutenant who has since split with Mr Sharif.

The verdict’s electoral impact hinges on what Mr Sharif does next. He has said he will return to Pakistan from London to “face jail”—but only after his wife, Kulsoom, who is being treated for throat cancer in London, regains consciousness. Mr Sharif’s recent absence from the campaign trail seems to be hurting the PML-N. The latest sounding by Gallup, a polling firm, shows the PTI has closed a previously sizeable gap and is now level pegging with Mr Sharif’s party.

Pictures of Mr Sharif in handcuffs would electrify supporters. And risking prison by returning to Pakistan would bolster his claim to be a selfless defender of democracy from military meddling, rather than a self-serving politician caught with his beak in the till. Lawyers doubt the NAB would grant Mr Sharif bail, however, preventing him from holding the kind of blood-and-thunder rallies that are probably needed to tilt the race back in the PML-N’s favour. He might instead suffer the indignity of watching his party lose from behind bars. In other words, if he stays in London, the party will suffer; if he returns, he will. Look through the window of a grand apartment in central London over the next few days, and you might spot a politician pacing up and down.

Correction, July 7th 2018: An earlier version of this article misstated the name of Zahid Hussain, the columnist.