Former Indonesian president Megawati Sukarnoputri is to stand for re-election again in July.
President Susilo Bambang Yudhoyono has already announced he is running again.
On Friday, he confirmed his vice presidential running mate would be central bank governor Boediono.
Vice President Jusuf Kalla is expected to confirm his nomination on Saturday.
President Yudhoyono has an approval rating of 67%, against 12% for Megawati and 2% for Kalla.
Boediono, 66, is a respected technocrat who is welcomed by analysts because of his clean image.
He confirmed on Friday he had submitted his resignation as central bank governor.
Megawati's announcement was also made on Friday. She lost to Yudhoyono in 2004 elections.
Megawati will run with Prabowo Subianto, a former general who has faced questions over his human rights record in the Suharto era.