Representatives Antonio Cuenco of Cebu and Eduardo Veloso of Leyte said the amount was "overly generous," not to mention the timing since renegade soldiers were then allegedly planning to launch a coup against the administration.
Cuenco said Estrada obviously wants to "influence the soldiers by giving millions of pesos" to a military cooperative.
"Who are they kidding?" he said.
"They are fooling the people by telling the whole world that their donation to the military has nothing to do with the destabilization plot against the government.
"We cant help but believe that the donation had something to do with the anti-government sentiments demonstrated by some members and officers of the Marines and Scout Rangers at the height of the chaos in Metro Manila last week," the lawmakers said in a statement.
Cuenco said Estradas involvement in past destabilization attempts against the government was established after former starlet Laarni Enriquez, one of his past mistresses, was linked to the failed Oakwood mutiny when her Mandaluyong City townhouse was used as the planning venue by the mutineers.
"The Estradas intention for donating the huge sum of money was clear and no amount of documents can convince the people otherwise," he said.
On the other hand, Veloso said the Estradas donation to elite military units was only one documented transaction.
"How about the others still unearthed?" he asked.
"How about the clear evidence that the Estradas were involved in the Oakwood mutiny? It was clear the Estradas wanted sympathy and support from some members of our Armed Forces.
"But we believe the bulk of our soldiers will remain professional and wont be lured by any form of financial enticements from the Estradas."
Veloso said the police and military should conduct an extensive investigation on the issue "as part of determining who were the financiers of the recent coup plot" meant to oust Mrs. Arroyo.
"It should include the possibility of the pork barrel of Senators Jinggoy and Luisa Loi Estrada getting into the Saludo sa Kawal Foundation and being channeled to the military cooperative," he said.
Veloso said the Estradas could have donated money to military units to divide the Armed Forces as part of an effort to destabilize the administration.
"It was clear the Estradas wanted sympathy and support from some members of the Armed Forces," he said.