Introduction
Former Deputy Speaker National Assembly of Pakistan, Qasim Khan Suri shared a picture from his verified Facebook account, the picture contains list of names of passengers boarding on April 4, 2022 claiming Nawaz Shareef cancelled his boarding on Flight PK-786 scheduled for departure from London to Islamabad 3 April, 2022 amid cancellation of No Confidence Voting.

(Screenshot from the post)
At the time the information was retrieved; the post was shared over 5.5 K times with 1.9K comments.

Debunked Source
https://www.facebook.com/Qasimkhansuri.PTI/posts/531860081638702
Archive
Fact Check
We tracked the Pakistan International Airline Flight PK-786 and found that PK-786 never took off from London to Islamabad on 3rd April , 2022, instead the last flight PK-786 took was a domestic flight between RYK>LHE on February 26, 2021 and is nonfunctional after last arrival in Rahimyar Khan.
Further research found that only flight that landed in Islamabad on 3rd April, 2022 was PK-9786 at 9:30 am which was before the dissolution of national assembly.

(Screenshot from the website)
According to reports by The Aviation Herald, ATC first lost contact with Flight PK-786 whilst in German airspace. After passing into Czech airspace, Czech ATC was also unable to get a response from the crew of the Pakistan International Airlines Boeing 777 after multiple attempts to make radio contact. Czech fighter jets were scrambled to escort Flight PK-786 to the border. After the incident European Aviation Safety Agency (EASA) banned PIA for safety reasons in European Airspace over concern of PIA Aircrafts Registered for Europe & dubious pilot license issue.
Source
https://flightaware.com/live/flight/PIA786
https://simpleflying.com/pia-777-radio-contact/
https://www.dawn.com/news/1636592
Rating
Propaganda/ Hoax

Conclusion
Former deputy Speaker of National Assembly Pakistan claimed via Facebook post that Pakistan Muslim League Nawaz leader Nawaz Shareef cancelled his boarding on Flight PK-786 scheduled for departure from London to Islamabad 3rd April, 2022 amid cancellation of No Confidence Voting against former Prime Minister of Pakistan Imran Khan. The post was shared to defame the opposition party’s Leader Mian Muhammad Nawaz Sharif.
ABCDE Framework-Based Analysis and Assessment
Actor | Social media users on Facebook and Twitter and verified official account of a ruling party are involved in disseminating the misleading content. |
Behavior | Misleading statements, doctored and edited videos with fake voiceover are posted, old pictures with misleading captions or false claims are posted and circulated widely on Facebook and twitter. |
Content | Social Media post, doctored videos with misleading captions. |
Degree | Disinformation is spreading hoax and misleading general social media users in Pakistan. Doctored videos are causing heated debates among rival political party supporters. |
Effect | Disinformation is causing distrust in the media; parody account of well-known media outlet is deceiving people in the name of entertainment. Doctored videos that go viral on social media cause heated arguments among party supporters. |
Analysis | Parody accounts of Media outlets, verified account of front-line political leader and social media users are spreading fake news to mislead the general public which leads to blame game, hate speech against party supporters and chaos. |