Pakistan’s Interior Ministry Chief Rehman Malik speaks during a press conference in Islamabad, Pakistan on Monday, March 9, 2009. Pakistan’s top security official warned opposition leader Nawaz Sharif that recent anti-government speeches he has given amounted to treason. (AP)

ISLAMABAD, Pakistan (AP) - Pakistan’s shaky government has threatened to charge the leader of the opposition with sedition after he called for protests against the president, raising the stakes in a political crisis that threatens to weaken the country’s fight against al-Qaida and Taliban.

Lawyers and supporters of opposition leader Nawaz Sharif have vowed to blockade parliament later this week over the refusal of President Asif Ali Zardari’s government to reinstate fired judges.

Pakistan was thrown into political chaos last month when the Supreme Court barred Sharif and his brother from elected office. Since then, both men have led an increasingly vocal campaign against the government, staging near daily anti-government rallies.

Interior Ministry chief Rehman Malik warned Monday that Sharif’s speeches in recent days came close to breaking the law.

"Inciting people for disobedience is sedition," Malik told a televised media conference. "It could get life imprisonment."

Malik said the government had "no intention" of arresting Sharif, but hinted it had grounds to do so, especially if violence broke out during the protest at parliament. Any arrest of Sharif or other high-profile members of his party would likely escalate the crisis.

Hours earlier, Sharif told a large crowd of supporters "we cannot leave Pakistan at the mercy of Zardari,"

"People should rise and join the long march to Islamabad to save Pakistan," he said. "The emotion I am seeing here is a prelude to a revolution."

Malik said the government would not ban the march, but that the protesters would not be allowed to rally in front of the parliament building or in other downtown areas.