Is the determination of the executive branch of the government that a state or instrumentality is entitled to sovereign or diplomatic immunity subject to judicial review, or is it a political question and therefore, conclusive upon the courts?

●It is a recognized principle of international law and under our system of separation of powers that diplomatic immunity is essentially a political question and courts should refuse to look beyond a determination by the executive branch of the government, and where the plea of diplomatic immunity is recognized and affirmed by the executive branch of the government x x x it is then the duty of the courts to accept the claim of immunity upon appropriate suggestion by the principal law officer of the government, x x x or other officer acting under his direction. Hence, in adherence to the settled principle that courts may not so exercise their jurisdiction x x x as to embarrass the executive arm of the government in conducting foreign relations, it is accepted doctrine that in such cases the judicial department of government follows the action of the political branch and will not embarrass the latter by assuming an antagonistic jurisdiction. (DFA vs. NLRC, G.R. No. 113191. September 18, 1996 citing World Health Organization vs. Aquino, G.R. No. L-35131, November 29, 1972) 

● The issue of petitioner’s (The Holy See) non-suability can be determined by the trial court without going to trial in light of the pleadings.  Besides, the privilege of sovereign immunity in this case was sufficiently established by the Memorandum and Certification of the Department of Foreign Affairs.  As the department tasked with the conduct of the Philippines’ foreign relations, the Department of Foreign Affairs has formally intervened in this case and officially certified that the Embassy of the Holy See is a duly accredited diplomatic mission to the Republic of the Philippines exempt from local jurisdiction and entitled to all the rights, privileges and immunities of a diplomatic mission or embassy in this country. The determination of the executive arm of government that a state or instrumentality is entitled to sovereign or diplomatic immunity is a political question that is conclusive upon the courts. Where the plea of immunity is recognized and affirmed by the executive branch, it is the duty of the courts to accept this claim so as not to embarrass the executive arm of the government in conducting the country’s foreign relations. As in International Catholic Migration Commission and in World Health Organization, we abide by the certification of the Department of Foreign Affairs. (The Holy See vs. Rosario, G.R. No. 101949, December 1, 1994)