MANILA, Philippines -- Even as she admits the just ratified Japan-Philippines Economic Partnership Agreement (JPEPA) is “flawed” and “imperfect,” Senator Miriam Defensor-Santiago is confident the Supreme Court will not stop the treaty’s implementation.

Santiago said she says the JPEPA taking effect in about a month after the Senate, voting 16-4, ratified the controversial trade pact late Wednesday night.

“Well, the two foreign ministers [of the Philippines and Japan] will send letters to each other with the information that the constitutional processes of the country had been complied with and, once that is exchanged between them, then the treaty comes into effect,” she told a press conference Thursday.

“That process should take let’s say a month,” she said.

Despite its flaws, Santiago said she is confident the JPEPA “would meet the test of constitutionality after a second exchange of notes between the two countries,” in case it is challenged before the high court.

The senator was referring to the exchange of notes this August between Foreign Affairs Secretary Roberto Romulo and his Japanese counterpart, Foreign Minister Masahiko Kamura, in which both countries agreed to observe each other’s existing laws.

Santiago said she doubts the Supreme Court would grant a petition for temporary restraining order (TRO) against the JPEPA since this would only bind the Philippine government.

“If the [high court] issues a TRO, the question then will be: That will certainly bind the Philippine government, but will it bind the Japanese government?” she pointed out.

“So it will be a question of whether the [Supreme Court] will stop a treaty, which will become executory at a certain date or at a certain point in time. And normally, the government does not do that because another state party is involved,” the senator said.

“It’s not only a question of Filipinos litigating among themselves, there’s another sovereign state involved. So I doubt very much if the [high court] will grant a petition for a TRO,” she said.

However, she also said if the Philippines should find the treaty disadvantageous, it may notify the Japanese government of its desire to terminate the agreement after a year.

She also noted that the treaty provides for a periodic review every five years.

“As I said, it is a flawed [and] imperfect document as I see it right now, [but] we’re hoping that, in the meantime, we could avail of the trade benefits from the treaty,” Santiago said.

“We expect, for example, big increases in foreign direct investment from Japan as well as proportionate increases in its official development assistance funds to the Philippines,” she said.

Other benefits of the treaty, the senator said, include a minimum or zero tariff for almost 95 percent imports from Japan and vice-versa, and the opportunity for Filipino nurses and caregivers to work in Japan.

She said the Philippines’ decision to enter into such an agreement would also send a message to the international economic community that the country has an open economy that is “hospitable” to foreign investments.

“Because, if we did not concur with the treaty last night, that’s to say, if we had rejected the treaty, then word would immediately spread in the global community that the Philippines is not a good place to invest,” she further said.

But opposition Senator Francis “Chiz” Escudero, who voted against the treaty, insisted the JPEPA was “poorly” and “badly” negotiated and would not be in the best interest of the country.

“Our negotiator should not be forgiven for not doing their homework, not following the letter and intent of our Constitution, not obeying laws passed by Congress, not protecting the best interests of our country and people and for selling out on our country’s birthright,” Escudero said in a statement.