"We are resigning from National Assembly, Punjab Assembly, Sindh Assembly, and Balochistan Assembly," Shah Mehmood Qureshi, the vice president of Pakistan Tehreek-i-Insaf announced, as the five-day political stand-off between the Pakistan government and anti-Sharif protestors intensified.
He said, for the time being, his party is not resigning from the Khyber Pakhtunkhwa Assembly, as there is a coalition government in the province and the allies will have to be taken into confidence before making such a big decision.
The Sharif-led government's offer to discuss all "constitutional" demands put forth by Khan's PTI and cleric Tahirul Qadri's Pakistan Awami Tehreek was rejected by the two protesting groups that have paralysed normal life in central Islamabad by staging sit-ins.
Khan, who has set a 48-hour deadline for Sharif's resignation and declared a "civil disobedience movement" against the government, did not respond to the late last night offer for talks.
The cricketer-turned-politician said there is no turning back and "nothing short of fake-mandated prime minister's resignation will be acceptable."
The PTI leader in a tweet said, "But I cannot keep these workers calm forever so in the interest of Pakistan, Nawaz Sharif shd resign immediately."
The firebrand Canada-based cleric also rejected the government's proposal outright and announced the plans to expand the 'Revolution March' country-wide if his demands were not met.
Qadri's 48-hour deadline for Sharif's resignation and formatting of a national government expires at midnight tonight.
"We will protest in four capitals of the provinces so that the people there can also join our revolution," he said.
Addressing thousands of his supporters camping at Aabpara square of Islamabad, the cleric said, "Time has come for a revolution."
Qadri also praised Khan's PTI on its "revolution", claiming the PAT and the PTI movements were working towards the same end goal.
"I say Zindabad to the PTI workers...they are our brothers. I congratulate Imran on announcing a two-day deadline" the cleric said.
Meanwhile, Qureshi said the resignations by PTI lawmakers are to be submitted to the relevant speakers Tuesday morning.
Qureshi said the decision was made after all other options were exhausted by the party in their protests against alleged rigging in the May 2013 general elections.
In the polls, Sharif's PML-N had won 190 out of 342 seats. Khan's PTI got 34 seats, the third largest bloc in the legislature.
The government late last night had announced formation of two committees, consisting of members from all major political parties, to hold talks with Khan and Qadri.
The decision to hold talks with the protest leaders came hours after Khan launched a civil disobedience movement to oust Sharif over alleged vote-rigging in the last general elections in 2013 that brought him to power.
Meanwhile, Army Chief General Raheel Sharif today met Punjab Chief Minister Shahbaz Sharif and Interior Minister Chaudhry Nisar Ali Khan in Rawalpindi, Dawn News reported.
During the meeting, it was decided that dialogue should be opened immediately with PTI and PAT to listen to their demands, the paper said.
Khan had on Monday declared a "civil disobedience movement" against the Sharif government, saying the country's future is bleak under the rule of businessmen.
The PTI chief has appealed to the people of Pakistan to stop paying utility bills and taxes to the current government.
Khan asserted that under the rule of "these businessmen who only want to make money for themselves, Pakistan's future is bleak." His remarks were directed at Sharif, one of the country's wealthiest person and the owner of Ittefaq Group.
Khan and Qadri had separately launched protests from eastern city of Lahore on Thursday, Pakistan's Independence Day, to dislodge the 15-month old Sharif government and have been camping in the capital since Saturday with thousands of their supporters.
The anti-government protests, however, appeared to lose steam as Khan's 'Azadi March' and Qadri's 'Revolution March' were unable to muster the numbers the two leaders had hoped for.
Opposition parties on Tuesday also distanced themselves from Khan's call for mass civil disobedience to topple the government.
Former president Asif Ali Zardari, co-chairman of the Pakistan People's Party, the largest opposition party, said Khan's willingness to use "unconstitutional means" to pursue his goals threatened democracy.
"Democracy and nation will not be served by calls for civil disobedience nor by a stubborn refusal by any side to engage in a meaningful dialogue on political issues," Zardari said in a statement.
Meanwhile, the Supreme Court rejected the government's plea seeking to restrain protesters from moving toward the capital's 'Red Zone' area, where the Parliament, the president and the prime minister's residences and embassies are located.
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