Pakistani opposition politician Imran Khan's party announced yesterday it is to renounce all its parliamentary seats, in a bitter row with the government over alleged poll rigging.
Former cricket star Khan claims last year's general election, in which his Pakistan Tehreek-e-Insaaf (PTI) party came third, was rigged and has demanded Prime Minister Nawaz Sharif resign and hold new polls.
The dramatic mass resignation came as the government tried to launch formal talks with Khan and populist cleric Tahir-ul-Qadri, who is leading a parallel protest, also calling for new elections.
Addressing his workers later in the evening, Khan said he would march on Islamabad's high-security "Red Zone" with his party workers and supporters on Tuesday.
"I will lead the march on the Red Zone and my workers will follow me," he told protesters, asking his party workers to remain peaceful during the march.
The heavily guarded Red Zone houses Pakistan's top government buildings and many foreign embassies.
Khan and Qadri on Saturday led thousands of supporters on a "long march" to the capital from the eastern city of Lahore, hoping to mobilise a mass movement to oust Sharif.
But Khan's protest failed to attract the vast crowds he had promised and other opposition parties on Monday shunned his call for a campaign of civil disobedience, leaving him looking increasingly isolated.
PTI vice-chairman Shah Mehmood Qureshi announced the shock mass resignation of MPs late on Monday afternoon.
"We are resigning from the National Assembly, Punjab Assembly, Baluchistan Assembly and Sindh Assembly," Qureshi told reporters.
He said the party was still making a decision about what to do in northwestern Khyber-Pakhtunkhwa province, where they are in power.
The MPs' resignations must be submitted to the national assembly speaker and passed on to the election commission. Qureshi did not say when this would happen.
PTI scored their best-ever performance in last year's election, which Sharif won in a landslide victory and was rated as free and credible by international observers.
They won 27 seats -- which will now go to by-elections -- and were awarded seven more through Pakistan's quota system for getting women and religious minorities into parliament.
Analyst Rahimullah Yusufzai said Khan had "isolated and weakened" himself with the civil disobedience call and the mass resignation was a risky gamble.
"This is an act of desperation. It will not bring the government under pressure -- it has already survived pressure of the march," he told AFP.