Makati City Mayor Jejomar Binay said such a probe will eventually lead to President Arroyo since it will necessitate investigating former Commission on Elections (Comelec) Commissioner Virgilio Garcillano.
According to Binay, the opposition would be more than willing to accept the challenge since it will open up a venue for a probe which will expose other electoral anomalies.
Binay, who is president of Uno, said they could investigate Madrigal themselves but the opposition does not have the authority to subpoena people, nor do they have control over the investigating agencies and other resources of government.
"Nonetheless, if the administration would give us a free hand to subpoena people and documents, we would welcome what they had been asking for since the highly questionable 2004 elections," he said in a statement.
The Makati mayor noted that any investigation on electoral fraud charges would entail bringing out Garcillano, as well as other Comelec and even National Movement for Free Elections (Namfrel) officials assigned to "key" areas then.
He added that they should also have access to the Mayuga report, which is a summation of the investigation supposedly done on military officers implicated in the "Hello, Garci" tapes controversy, which up to now has not been made public.
"Defensor may not have realized what he was saying at the time, but this may blow up in the administration’s face if they really want an investigation on electoral fraud," Binay said.