The decision was made at a meeting of the PPP's top leadership that was chaired in Karachi by President Asif Ali Zardari, who heads the party.
A statement issued after the meeting said, "some elements" were trying to disrupt the electoral system and postpone the elections.
The PPP's leadership reiterated the commitment of the government and the party to thwart any attempt to postpone the elections.
"The meeting made it clear that elections will be held on time as stipulated in the Constitution and no delay, even for a day, will be permitted on any pretext," the statement said. The PPP leaders met even as cleric Tahir-ul-Qadri, who heads the Tehrik Minhaj-ul-Quran, stepped up his calls for electoral reforms ahead of the general election expected to be held by May.
Qadri has said he will lead a "long march" from Lahore to Islamabad to pressure the PPP-led government into consulting the army and judiciary on forming a caretaker set-up to oversee the polls.
Though the PPP's statement did not name Qadri, insiders said the cleric had rattled the party's leadership. Over the past few days, Prime Minister Raja Pervez Ashraf has reached leaders of parties in the ruling coalition and opposition parties like PML-N chief Nawaz Sharif to discuss ways to counter the threat posed by Qadri.