Megawati and Prabowo have yet to officially clinch a deal for the presidential polls, as their parties failed to finalize their coalition Thursday.
Saturday is the deadline for presidential hopefuls to register with the General Elections Commission (KPU).
Sources at Megawati's Indonesian Democratic Party of Struggle (PDI-P) said coalition talks were entering "a critical situation" because no agreement with other parties, including Prabowo's Great Indonesia Movement Party (Gerindra) had yet been secured.
The party's lobbying team also met with their counterparts from the Prosperous Justice Party (PKS).
“I must admit it is a very critical situation for most political parties, not only the PDI-P but also the Democratic Party, as we are now in a race against time to decide on a vice presidential candidate,” said PDI-P secretary-general Pramono Anung.
The only candidate to have officially announced a bid is Jusuf Kalla, with Wiranto as his running mate.
Incumbent President Susilo Bambang Yudhoyono and his running mate Boediono will declare their candidacy in Bandung today.
With a 20 percent vote threshold required to nominate a candidate, the PDI-P's 15 percent in the legislative elections and Gerindra's 4.6 percent could see the presidential poll become a two-horse race, unless a coalition can be formed to nominate Megawati as president and Prabowo as her running mate.
Of the two parties the PDI-P has lobbied, only the talks with Gerindra have progressed, Pramono said.
Megawati's daughter Puan Maharani said the sticking point was the proposed ticket's mutual acceptability among the two parties’ supporters at the grassroots level.
“We must explain almost everything to each of our own party members and supporters, and of course that takes time," said Maharani, a member of the PDI-P's executive board.
Another PDI-P source, speaking on condition of anonymity, said both sides had agreed on the ticket, but had postponed the official announcement to Friday, pending talks of "crucial matters", including campaign funding.
"The parties have two days to conclude the talks before they must register with KPU," the source said.
Another source said Megawati had accompanied her husband Taufik Kiemas at MMC General Hospital to prevent him disrupting the talks.
During intense lobbying last week between the PDI-P and the Democratic Party, Taufik said Gerindra was "part of the past".
Jajat Munajat, secretary of PDI-P’s Islamic wing Baitul Muslimin Indonesia, confirmed both sides had agreed to nominate the Megawati and Prabowo for the July 8 polls.
“The announcement will be made Friday at Megawati’s residence on Jl. Teuku Umar [in Menteng, Central Jakarta],” he said.
The talks between the PDI-P and Gerindra resumed Wednesday after both sides failed to build coalitions with other parties.
Jajat described the discussions over Megawati's vice presidential candidate as ”exhausting”.
A meeting, organized Thursday night and featuring intelligence figure Hendropriyono, PDI-P legislator Panda Nababan and Emir Moeis, discussed key issues such as campaigning funding, a source said.
“The latest info I got was that Gerindra would finance much of the campaign, but we still haven't found the right formula, and that's why we need to talk it over,” the source said.
