Up until her husband´s ousting past year, Kulsoom Sharif had never been a politician, but she memorably led protests after a 1999 military coup that ended a previous Sharif administration.
Begum Kulsoom had contested and won NA-120, a traditional bastion of the Pakistan Muslim League (Nawaz) after the seat fell vacant following Nawaz Sharif's disqualification by the Supreme Court (SC) in the Panama Papers case. "May her soul rest in peace", Shehbaz Sharif said in a twitter announcement.
Nawaz Sharif and Maryam Nawaz, who are serving sentence in Adiala Jail, have also been informed about the demise of Begum Kulsoom.
Three-time-premier Nawaz Sharif, who was removed from office in each of his elected terms, has maintained that his ouster in July 2017 and subsequent conviction were part of a plot against him by the powerful military and the judiciary.
The Musharraf regime eventually allowed Nawaz and Kulsoom Sharif to leave the country, and they spent years in exile until returning in 2007 to contest new elections after Musharraf stepped down in the face of mass protests.
The prime minister has directed the Pakistan High Commission in London to assist in provision of all necessary facilities to the family of the deceased, news agency PTI quoted his statement.More news: Zinedine Zidane confirms coaching return amid Manchester United link
Begum Kulsoom served as the first lady of Pakistan for three non-consecutive terms from 1990-1993, 1997-1999 and 2013-2017.
Her first direct exposure to the harsh political landscape of Pakistan came in October 1999 when her husband's government was toppled and he was imprisoned.
Begum Kulsoom was elected to Lahore's NA-120 constituency in a by-poll after her husband was disqualified from the seat by the Supreme Court previous year, but left for the United Kingdom before she could begin campaigning for the by-poll.
Both sons Hassan and Hussain reside in the United Kingdom and cared for her while Nawaz and Maryam attended near daily hearings of their corruption trial.
Arif Alvi condoled the bereaved family.
Politicians from various political parties and high-level government officials also expressed deep grief over the death.