Ousted Pakistani Prime Minister Nawaz Sharif and his daughter Maryam, both sentenced to lengthy prison terms in absentia, are due to return to Pakistan.
Authorities have mobilized thousands of police officers ahead of their arrival in the city of Lahore on July 13 and have blocked key roads leading to the airport.
Sharif's Pakistan Muslim League-Nawaz (PML-N) party say authorities have arrested hundreds of party members in recent days to prevent them from staging a rally upon Sharif's return.
Mushahid Hussain Syed, a senator and head of the PML-N's media committee, told RFE/RL on July 12 that a "huge crackdown" has been launched against the party.
PML-N leaders have accused Pakistan's powerful military, which has an influential role in domestic and foreign affairs, of attempting to destabilize the party ahead of general elections scheduled for July 25.
Sharif, ousted by the Supreme Court for corruption last July, was convicted last week and sentenced to 10 years in prison over purchases of luxury apartments in London.
His daughter Maryam was sentenced to seven years in a case stemming from the 2016 Panama Papers leaks.
Both were sentenced in absentia while in Britain, where Sharif's critically-ill wife is in the hospital.
Sharif has not yet appealed his conviction and is expected to be taken into custody as soon as he lands in Lahore.