Ali Musa, a parliamentarian, insisted that his guard, who had an economy class ticket, would sit with him in the business class, The Express Tribune reported.
The matter was resolved when the captain of the flight intervened and told the premier's son that he would turn the aircraft back to Lahore if he persisted with his demand, which was against the rules.
The threat by the captain worked and Ali Musa gave up his demand, following which the flight continued and landed at Karachi, the report said.
The report did not say when the incident had occurred.