Key leaders of opposition parties in Karachi met Chief Election Commissioner Fakhruddin G Ebrahim at the Election Commission's provincial office last week, demanding military supervision of the voter verification process in Karachi.

"The military is asked to assist the commission's personnel in Karachi wherever there is a threat," the CEC said after the meeting, "and military men are generally escorting the election commission staff when voters are verified."

But he said new delimitation of constituencies was not possible without a census. "We can't delay the elections, so went for voter verification at a faster pace. I had asked for over 17,000 troops for voter verification but was given just enough to do the job."

Outside the EC office, there was a sit-in protest led by Jamaat-e-Islami's Mohammad Hussain Mehnati, JUI-F's Hafiz Ahmed, PML-N's Saleem Zia, PML-F's Jam Madad Ali, JUP's Shah Owais Noorani, PTI's Saeed Hafeezuddin, Sunni Tehrik's Matloob Awan, and JUI-S' Ghulam Farooqi. Some of them said the elections would be "hijacked" and the commission won't act.

"Fakru Bhai should tell us why he is not implementing the judgment of the Supreme Court of Pakistan," said Hafiz Hussain Ahmed. "We do not doubt his honesty and have always respected him, but we do not understand why he has gone back on his word on delimitation."

Ayaz Palejo of the Sindhi ethnic party Awami Tehrik said he was "disappointed" with the EC's decision not to carry out a fresh delimitation of the constituencies in Karachi.

An important concern ahead of elections in the city is political violence. At least 2,193 people were murdered in targeted political and sectarian killings during 2012.

Sarwat Ejaz Qadri, chief of Sunni Tehrik, said it was "impossible to hold peaceful elections with hundreds of people being killed by banned militant groups" linked with Taliban and Al Qaeda. "I fear that the coming elections will be the bloodiest ever."

Afaq Ahmed, chairman of MQM-Haqiqi, said about 1,000 of his close aides had been killed in last five years. "How can we have peaceful elections in Karachi with thousands of innocent people killed in political violence?" he said. "The MQM wins by force. We need the military to do an operation to ensure free and fair elections."

Mustafa Azizabadi, in charge of MQM's London secretariat, said his party had no issues with the EC. "We don't have a problem with voter verification or with the military coming to Karachi to assist the process. We had won the election in the 1990s despite the military operations, with a record number of people coming out to vote for MQM."

Senior provincial minister and veteran PPP leader Agha Siraj Durrani said election violence would hurt all political parties. "We are working with all the stakeholders for peaceful elections, and you will soon see results," he said.

A source in the military who asked not to be named said a special cell headed by a serving colonel had been setup in the ECP office in Karachi for coordination and rapid response.

The PPP currently holds 91 of the 166 seats in the Sindh Assembly, the MQM 51, PML-Q 9, PML-F 10, NPP three, and the ANP has two seats. The MQM has consistently won more than 80 percent of urban seats since the 1988 elections, and the PPP wins more than 70 percent of rural seats.