Senate President Franklin Drilon said the Australians should expect the treaty to face rough sailing as it involves the protection of national interest.
"Any attempt to diminish the sovereignty of the country will always be challenged in the Senate," Drilon said.
"It is now up to the Department of Foreign Affairs, Malacañang and the Australian government to convince the senators that the SOFA is in the national interest of the Philippines," he added. "The yardstick will always be our national interest when we are confronted in the Senate with treaties of this nature."
Senate Minority Leader Aquilino Pimentel Jr. said the goal of the Senate is to ensure that the Philippines does not face any disadvantages due to the agreement.
"We have every right to look into that and we will do what needs to be done for the good of the country," he said.
Pimentel, however, disclosed that military exercises with the country’s allies would always be welcome as long as the interests of the country are protected.
Senate committee on foreign relations chairman Miriam Defensor-Santiago said that the proposed SOFA should be handed over to the Senate as soon as possible.
The Senate is the only constitutionally mandated body with the power to ratify and abrogate international treaties entered into by the Philippines.
Because of the ongoing investigation into the alleged rape of a 22-year-old Filipina by US servicemen, Santiago said the Visiting Forces Agreement (VFA) with the United States should be tested first before a similar agreement is replicated with Australia.
Australian Defense Minister Robert Hill said he expected the proposed SOFA to be carefully scrutinized in the Philippine Senate but emphasized the need for the agreement.
"We think that it is in our interest to help the Philippines more effectively meet the threat of terrorism in Mindanao and other parts of southern Philippines because we believe that it is not only a threat to them but also a threat to us," he said. — Marvin Sy