In light of the Supreme Court ruling on the Panama Papers case, the Lahore High Court Bar Association (LHCBA) on Saturday gave an ultimatum to Prime Minister Nawaz Sharif: resign within a week, or face a lawyers' movement bigger than the one that followed ex-chief justice Iftikhar Chaudhry's ouster in 2007.

The demand comes days after the Panama Papers case verdict was announced, directing that a Joint Investigation Team (JIT) be instituted to investigate the prime minister and his sons for alleged corruption.

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However, opposition parties have expressed reservations on the integrity of a probe against the premier carried out by officials that the PM himself has appointed.

The Pakistan Tehreek-i-Insaf (PTI), PPP and Jamaat-i-Islami (JI) have all demanded that the PM resign until the JIT has completed its investigation.

LHCBA President Zulfiqar Chaudhry, vice-president Rashid Lodhi, secretary Amir Saeed Raan and finance secretary Zaheer Butt presented their demand for the PM's resignation at a press conference. Chaudhry stressed that if the prime minister does not relinquish his post within a week, they will launch a movement bigger than the lawyers' movement for restoration of the deposed judges.

"The [Panama Papers case] decision is unanimous," said Chaudhry, referring to Thursday's verdict.

"Throughout the world, public office holders implicated in the Panama [Papers] scandal have relinquished their posts, but the prime minister is adamant to stay in power," he complained, emphasising that the bar association's demand for PM's resignation was legitimate and fair.

"How can officers under the PM conduct a fair investigation into the PM's alleged corruption?" asked Chaudhry.

Rashid Lodhi, vice president of the bar association said: "This is the first time such a high-profile case of corruption went up to the Supreme Court and some pertinent questions were raised by the court regarding the PM's money-trail. These questions can not be put ignored."

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He said the apex court has rejected the prime minister's claims, and for that reason, Sharif has lost the moral authority to stay in power.

"The SC verdict has, in effect, indicted the prime minister," said Amir Saeed Raan, secretary of the LHCBA.

"Two of the five judges have made it clear that the PM is not 'Sadiq' and 'Ameen'," he stated, adding that the prime minister should have the courage to resign, instead of letting his own appointees investigate him for alleged corruption.

The legal fraternity in Pakistan flexed its muscles back in 2007, when ex-president Pervez Musharraf ousted the then chief justice Iftikhar Chaudhry. The lawyers' movement that followed, gained enough momentum to result in the reinstatement of the deposed judiciary.

The LHCBA representatives stressed that their demand must not be seen as to be politically motivated.