The Pakistan government on Monday threatened ex-premier and main opposition leader Nawaz Sharif with charges of sedition for inciting people to rebellion after a court barred him from public office.
Interior ministry chief Rehman Malik cited the relevant sections of Pakistan penal code, saying that expressing hatred or contempt against the federal or provincial government was punishable by life imprisonment.
"Their statements fall in the (category of) sedition," he said in reference to the country's most popular opposition leader Nawaz Sharif and his brother Shahbaz.
He read out phrases from speeches he said Nawaz Sharif has made since the supreme court disqualified him and his brother from contesting elections and holding public office.
Sharif has made speeches calling on the police not to obey government orders and attacked judges who disqualified him saying he does not recognise the rulings of the supreme court -- the highest in the country.
The politician has joined forces with lawyers who are organising a march to demand the reinstatement of supreme court chief justice Iftikhar Muhammad Chaudhry and other judges sacked by former military ruler Pervez Musharraf.
Malik said the government would respond with force if protesters damaged property during the so-called long march, which lawyers and opposition political parties are planning from Karachi to Islamabad on March 12-16.
"If any death occurred or public property is damaged then the government will invoke sedition law against him (Nawaz Sharif)," Malik said.
The interior ministry chief called on protesters not to march on parliament as planned, where the lawyers have called for an indefinite sit-in.
"I have asked them not to come to Constitution Avenue and requested them to gather at an alternate place in Islamabad," Malik said.
"I have asked the security force to take maximum security measures".
Analysts said his comments underscored the nervousness of the weak civilian government after Sharif has mobilised rallies of thousands of supporters in the Punjab political heartland outside Islamabad for nearly two weeks.
"We want peaceful demonstration, peaceful processions within the perimeters of the law," said Malik.
"The information that we are receiving indicates that threat is there."
Pakistan was criticised for poor security after 12 attackers ambushed the Sri Lankan cricket team in the eastern city of Lahore last week.
"The people who attacked (the) Sri Lankan team in Lahore can attack the long march also. The enemy would like to harm Pakistan," he added.