Khan, who was ousted as PM by his opponents in 2022, is already serving a three-year jail term after being convicted of corruption.
On Tuesday he was sentenced for leaking state secrets, and on Wednesday given 14 years in another corruption case.
Khan has said the numerous cases against him are politically motivated.
Khan retains immense popularity across the country but has been barred from standing in the 8 February vote. His party, the Pakistan Tehreek-e-Insaf (PTI), has also faced campaigning restrictions.
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