Ousted Pakistani Prime Minister Nawaz Sharif is returning to Pakistan despite facing a 10-year jail sentence for corruption.
Ousted Pakistani Prime Minister and his daughter Maryam both face arrest when they arrive back in Lahore from London on Friday.
Authorities have mobilised more than 10,000 police officers ahead of their arrival and plan to block roads with shipping containers to shut down the city of Lahore.
The three-term PM was ousted from office last year after a corruption investigation. He was sentenced in absentia to 10 years last week.
He has accused Pakistan's security establishment of conspiring against him ahead of July 25 elections.
"There was a time when we used to say a state within a state, now it's a state above the state," Nawaz Sharif told supporters of his Pakistan Muslim League-Nawaz (PML-N) party in London on Wednesday.
"Despite seeing the bars of prison in front of my eyes, I am going to Pakistan", Ousted Pakistani Prime Minister added.
Hundreds of party activists in Lahore are reported to have been detained ahead of his return.
Sharif, 67, has been one of the country's leading politicians for most of the past 30 years.
In May, the Dawn newspaper published an interview with Sharif in which he questioned the wisdom of "allowing" Pakistani militants to cross the border and kill 150 people in Mumbai, referring to attacks in the Indian business capital in 2008.
The military, which has ruled Pakistan for about half of its 70-year post-independence history, has denied it has any "direct role" in the elections or the political process.
Although he was disqualified from standing in the upcoming election by the Supreme Court, Sharif remains one of the most popular politicians in Pakistan, especially in Punjab, the most populous and electorally significant province.
