The European Union is weighing in against legislation to let the families of Sept. 11 victims sue Saudi Arabia over its alleged support for people who carried out the attacks.

In a letter to the State Department, the European Union delegation to the United States called on President Obama “to act in order to prevent the JASTA bill from becoming law,” referring to the acronym for the “Justice Against Sponsors of Terrorism” bill and urging him to “act to obtain the stay of proceedings” if the legislation comes into force.

The letter, which appears to have been sent Monday, was circulated by Saudi-contracted Qorvis Communications on Wednesday. The EU’s delegation to the United States said on Twitter Wednesday that while they would not comment on leaked diplomatic exchanges, it is “true that we share US concerns” about the measure’s effect on foreign sovereign immunity.

The delegation also stressed that while there was “no threat of reciprocity from the EU,” both the EU and the United States were “concerned about possible reciprocity from others.”

JASTA would let courts waive foreign countries’ claims to sovereign immunity in cases involving terrorist act on U.S. soil. The Saudi government has protested that it had nothing to do with the Sept. 11 attacks, but has still been lobbying hard against the legislation.

The White House has threatened to veto the bill and has until Friday night to do so. Congressional leaders expect to hold an override vote soon afterwards. They are also confident they have the numbers to overcome the president’s veto, despite many members voicing last-minute qualms about repercussions from other countries, who might use the bill as an excuse to drag the U.S. into court over its more controversial foreign engagements.

When asked about the E.U. letter Wednesday, Senate Foreign Relations Committee ranking member Ben Cardin (D-Md.), who has not said how he will vote on the expected override – seemed nonplussed.

“Well, you know ,we’re not getting along with the EU right now. Look at Apple,” he said, referencing Europe’s recent determination that Apple owes $14.5 billion in back taxes.