Altaf Hussain, the former leader of the Muttahida Qaumi Movement which once ruled Karachi, faces up to seven years imprisonment for the speech which was "likely to be understood" as encouraging supporters to acts of terrorism.
British police have charged a Pakistani political exile with encouraging terrorism, Scotland Yard announced on Thursday, after a speech he made in 2016 to supporters in Karachi was followed by violent protests.
Altaf Hussain, the former leader of the Muttahida Qaumi Movement (MQM), which once ruled Karachi, faces up to seven years imprisonment for the speech which was "likely to be understood" as encouraging supporters to acts of terrorism, or was "reckless" of the possible consequences.
Hussain, 66, has lived in London for more than two decades and often addressed supporters in the South Asian megacity through a loudspeaker linked to his home telephone.
In the speech on August 22, 2016, he castigated the media for not giving due coverage to his workers. Police accused him of chanting anti-Pakistani slogans, and security forces moved in to seal his party headquarters.
MQM activists clashed with police and ransacked a private TV station in violence which left at least one man dead and seven others injured.
Hussain's party "completely disowned" him after the statements, splitting in to two factions — MQM Pakistan, and Hussain's shrinking group which he continued to run out of London.
Pakistan later charged him with treason and inciting terrorism. He has lived in London since fleeing a military operation against his party in 1992, and is a British citizen.
The MQM, long accused of using extortion and murder to cement its grip on power, was blamed for years of ethnic violence in Karachi.
It clashed repeatedly with authorities until security forces launched a brutal "clean-up" operation in 2013 that was plagued with accusations of extra-judicial killings and which has seen political violence drop significantly in the southern port city.
The MQM lost its hold on Karachi during 2018's general election, with the party's Pakistan faction now allied with Prime Minister Imran Khan's ruling Pakistan Tehreek-e-Insaf party.
Hussain still publishes periodic messages denigrating the Pakistani establishment on social media, though as his grip on power has diminished his audience has shrunk dramatically from their peak during his charismatic speeches of the 1980s and 1990s.
He was due to appear in a magistrates court in London on Thursday.