Estrada claimed that they have received information that the People Power Coalition (PPC) would no longer campaign in Mindanao and would let a "special operation team" do the dirty work for the administration.
"They know that they have no chance of winning in Mindanao. Binabato sila ng kamatis at sinisigawan doon (They are being pelted with tomatoes and hooted down there)," he said.
Estrada said the opposition already knew who are involved in the "special operations" but declined to identify them, or to reveal their base of operation.
"I will give detailed information in due time," he vowed.
He warned the administration coalition against proceeding with the alleged special operation, saying the people would not take any thwarting of their mandate lying down.
He has repeatedly spoken of a "revolution" should there be massive cheating.
Estrada said they have organized groups to counter any attempt to cheat the opposition out of victory in the May 14 elections.
He also lashed at the PPC for the "harassment" the opposition senatorial slate reportedly suffered during their campaign sorties in Iriga City and Naga City, both in Camarines Sur.
The opposition claimed that Naga City Mayor Sulpicio Roco refused to give them a permit to hold a rally at the Quezon Plaza the other night, while the National Power Corp. (Napocor) cut off power in Iriga where the opposition was supposed to hold a simultaneous grand rally.
"Intimidation, threat, lahat ng klase ng (all kinds of) harassment, the Bureau of Internal Revenue  gagamitin nila laban sa oposisyon (they will use against the opposition)," Estrada claimed.
Roco denied that there was anything political when the rally permit was denied.
He said he approved a March 2 application of the Sangguniang Kabataan of Abella for the March 30 rally, and that he would have approved the opposition’s application had he received it earlier.
"In fact, I would have wanted to use the plaza for our proclamation rally as the day marked the start of the local campaign, but I couldn’t because I had already given the Abella youths a rally permit," Roco said.
The Iriga rally pushed through after the Napocor cut off power for only two hours. However, Estrada and the opposition’s senatoriables did not proceed to the city because of heavy rain.
The downpour made some opposition campaigners suspect that the administration even seeded the clouds over Camarines Sur to minimize crowd attendance.
"That is possible  the administration will do anything," Estrada said of the cloud-seeding charge.
He expressed confidence that his wife, Dr. Loi Ejercito Estrada, would win in the elections, as he downplayed the results of the Social Weather Stations survey where she placed 19th.
Meanwhile, Estrada said he harbors no ill-feeling toward actress Nora Aunor, who is running for governor of Camarines Sur under the administration ticket.
"Wala akong hinanakit. She was merely carried away by her emotion," he said.