Its neighbours are an Afghan restaurant, a cafe selling fried chicken and a boarded-up, Tudor-style pub. But it is from this first-floor office in north-west London that the Pakistani megacity of Karachi, 4000 miles away, is remotely governed by a flamboyant and controversial British citizen.
The office is the headquarters-in-exile of the Muttahidi Quami Movement (MQM), Karachi's most powerful political party. Its leader, Altaf Hussain, has lived in the UK since 1991. These days, he rarely visits his HQ, but his portrait hangs on the wall next to coloured maps of Pakistan's provinces, a list of MQM candidates who recently took part in Pakistan's general election, and a silver statue of a fist.
On Saturday Imran Khan, the cricketer-turned-politician, accused the London-based MQM leader of being "directly responsible" for the murder of Zhara Shahid Hussain, a senior female member of Khan's Movement for Justice party (PTI). Hussain was shot dead outside her house in Karachi's upmarket Defence neighbourhood. Her driver, who witnessed her murder, is now in police custody.
The sequence of events was this: after Hussain emerged from her car, a man sitting on a moped with an accomplice rushed towards her. Assuming she was being mugged, she threw down her handbag and mobile phone. The man pointed his gun at her forehead. She tried to defend herself, pushing the gun away, only for it to fire into her jaw. The man shot her again, in the back. "If this was a mugging incident, why did he [the assassin] leave the wallet?" Ahmed Chinoy, head of the Citizens Police Liaison Committee, asked.
A furious Khan also berated Britain. He suggested that Downing Street had failed to heed his claim that Altaf Hussain was responsible for numerous incidents of torture and murder in Pakistan. In 2007, Khan presented a dossier to No 10, urging it to arrest and prosecute the MQM leader using anti-terrorism laws.
On Saturday, Khan tweeted: "I also hold the British Govt responsible as I had warned them abt Br citizen Altaf Hussain after his open threats to kill PTI workers."
The dispute marks a new low in the already bitter rivalry between Khan's party and the MQM. The PTI accuses the MQM of preventing its supporters from voting during the elections, 10 days ago. (The poll was rerun last Saturday in 43 Karachi polling stations; the PTI cruised to victory after the MQM and others boycotted it.) More broadly, Khan alleges that Britain has ignored the MQM's violent record. The UK's liberal traditions have in this case enabled cold-blooded murder on Karachi's already febrile streets, he says.
After Khan's complaints, the Metropolitan police is investigating a speech made by Altaf Hussain from London last week. The investigation is in its early stages. The British foreign office said on Saturday evening it "strongly condemned" all acts of violence in Karachi, including Hussain's murder. It added: "We are deeply saddened by the recent violence in the city, including violence murderously directed against democratic political figures."
The MQM vehemently rejects Khan's allegations. It is now suing him for defamation in Pakistan's high court, and says it will do the same this week in Britain. In a statement on the party's website , Hussain says he had nothing to do with Zhara Shahid Hussain's brutal death. Expressing his condolences to her family, he urged Pakistan's government to find the killers and administer "exemplary punishment".
Hussain has not given an interview for some years. His aides in London say he is "unwell". YouTube footage of his British press conferences show him as a larger-than-life figure prone to wild verbal performances characterised by finger-wagging and odd gestures. His campaign speeches are broadcast from chilly, overcast London to the Karachi faithful, many of them women who hold portraits of their tubby, moustachioed leader.
Speaking from the MQM's office, in Edgware, Mohamad Anwar, one of Hussain's advisers, said the party was a legitimate democratic movement. Hussain founded the MQM in the 1980s to defend the interests of the Muhajirs, the Urdu-speaking descendants of Muslims who moved from India to Pakistan during partition, in 1947. They arrived in a city then dominated by native Sindhis and Baloch. The MQM's political strongholds are urban Karachi and Hyderabad, in Sindh province; it is at odds with Pakistan's Punjabi-dominated elite, Anwar says.
Critics say that from its earliest days the party showed a readiness to use violence to fight for power.
In the 1980s, when Hussain felt newspapers were giving him insufficient coverage, MQM supporters began burning all the city's papers before they could be distributed. "He forced all the media owners to come to the 90 [the party's headquarters] and beg his pardon," said Muhammad Ziauddin, managing editor of the Express Tribune. One paper protested by refusing to publish for one day.
Over the last five years, the MQM has proved to be an extremely troublesome coalition partner, temporarily walking out of the government several times when it didn't get what it wanted. Critics say that when political blackmail fails, it turns to street violence.
"MQM has the ability to dial up and dial down violence when certain political objectives are threatened," said Shamila Chaudhary, a senior analyst at the Eurasia Group. "It's not new, but now they are feeling particularly threatened in their historic domain."
After successfully asserting its authority over Karachi in the 1980s and 1990s, when the military launched operations against the party, the MQM's power base is now under attack. One problem is profound demographic change: the city is filling up with Pashtuns fleeing Talibanviolence in the north-west of the country. One informal estimate puts their numbers as high as 25%.
More of a surprise to the MQM is the rise of the PTI. Imran Khan's party had a disappointing result nationally, winning 28 seats, fewer than it had hoped. But in Karachi it managed to snatch nearly 20% of the vote.
Undoubtedly, however, Khan wrested votes from the MQM's core of middle-class supporters. Nusrat Javed, a prominent journalist, said: "The PTI is giving voice to the accumulated rage of middle-class, upwardly-mobile professionals who think the MQM got stuck in the 1980s."
Hussain's followers dismiss claims of MQM wrongdoing. Of Khan's murder accusation, Anwar replied: "It's a madman's rant. Khan is a man who has utterly failed, having lost the elections."
Anwar said the MQM was itself a victim of political violence because of its secular beliefs and refusal to compromise with radical Islamists. The Pakistani Taliban frequently targeted and killed MQM party workers, he said. He denied claims that the party engages in extortion, land theft and other mafia-style activities, or that it has a shadowy armed wing.
Leaked diplomatic cables, meanwhile, show the US was impressed with the MQM's municipal record after it won control of Karachi city council in 2005. Its young mayor improved tax collection rates, built roads and devised water schemes in an overcrowded metropolis and port city of 16 million people. "The MQM based in Karachi appears to be transforming itself from a group of thugs to a service-based, grassroots political party," one diplomat wrote in 2008.
But why does its invisible leader live in self-imposed exile? "Look at what happened to Benazir Bhutto," Anwar said. "Would the Taliban spare him? They didn't spare Benazir." He added: "Benazir lived in London for many years; Nawaz Sharif was in Saudi Arabia. Mr Hussain is no exception." Anwar predicted that Pakistan's ex-president Pervez Musharraf, who was in London and is now under house arrest in Pakistan, would soon be coming back.
The bookshelf at Hussain's London HQ contains some unexpected reading: Imran Khan's autobiography, as well as books on Churchill and India's constitution. According to Anwar, Scotland Yard is worried the MQM's offfice, on Edgware High Street, could itself be the subject of an attack. A police sergeant calls round twice a day. These concerns may not be exaggerated: in 2010, Hussain's senior London-based ally Dr Imran Farooq was stabbed to death outside his Edgware home.
Why did the MQM have a copy of its arch-enemy's book, Pakistan: A Personal History? Anwar explained: "Of course we can read his autobiography. But Khan is an arrogant and immature man."