PPP Co-Chairman Asif Zardari will return to Pakistan on Dec 23, PPP Chairman Bilawal Bhutto-Zardari said on Sunday.

The PPP chairman, addressing a press conference, said Zardari's doctors had permitted him to make the trip to Pakistan and he would return on Friday, landing in Karachi.

The former president abruptly left the country last year after a hard-hitting speech where he lashed out at the military establishment for overstepping its domain. He had said that army chiefs come and go every three years, but the political leadership is here to stay.

Earlier in Nov, a source in the PPP told Dawn, "After the hard-hitting speech against the military establishment, Mr Zardari chose to go into self-exile in Dubai about one-and-a-half years ago as a clear message was reportedly given to him. Now the environment is conducive and Mr Zardari has announced his return to the country."

Read more: Zardari cautions military establishment for 'stepping out of domain'

Bilawal today was optimistic his party would put up "a strong opposition" against Prime Minister Nawaz Sharif's ruling PML-N, and said: "We need the great strategic skill of Zardari to overwhelm the Sharif government so that despite their two thirds majority, they will have to implement my four demands."

The PPP has threatened to launch an 'anti-government drive' on Dec 27 if its four demands are not met. The demands include: formation of a parliamentary committee on national security, adoption of a PPP-drafted bill on Panama Leaks probe, implementation of the decision of a multi-party conference chaired by Asif Zardari on CPEC and appointment of a full-time foreign minister.

"If Zardari is in Pakistan, our four demands will be fulfilled soon," Bilawal vowed.