Defense attorneys for a Mexican national sentenced to death in Texas, for the kidnapping, rape and murder of a 16-year-old girl in 1995, have asked the U.S. Supreme Court to grant a stay of his scheduled July 7 execution.

The petition for writ of certiorari and a stay motion - submitted Tuesday by Humberto Leal García's legal team - argues that the state of Texas should not be allowed to violate Leal's constitutional rights, nor impinge upon the institutional interests of the U.S. Congress and the executive branch in a "race to execution."

That request also cites an "overwhelming public interest" in ensuring that the U.S. government complies with a 2004 order from the International Court of Justice to review the death sentences of 51 Mexicans then awaiting execution in Texas.

In that March 31, 2004, ruling, the ICJ said Texas had violated the rights of Leal and other Mexican nationals by failing to inform them of their right to consular assistance under the Vienna Convention.

The Mexican government, in a separate "friend of the court" brief Tuesday, informed the high court that it has been a "forceful advocate" for U.S. citizens detained in Mexico and urged its neighbor to comply with its international treaty obligations.

Leal's defense attorneys called for the execution to be delayed to allow time for debate on a bill known as the Consular Notification Compliance Act - introduced June 24 by Sen. Patrick Leahy, a Vermont Democrat.

The defense team said the legislation, which is backed by the Obama administration, would enable foreign nationals convicted and sentenced to death to have their cases reviewed in federal court to determine whether denial of consular access affected the outcome of their trials.

With consular access, Leal would have qualified, experienced attorneys who would have "transformed the quality of his defense," Sandra Babcock, one of the convicted man's lawyers, said.

Leal, a 38-year-old native of Monterrey, was sentenced to death in 1995 by a Texas court.

The attorneys concluded their petition by urging the United States not to break its word and sully its international image by failing to comply with its treaty commitments under the Vienna Convention on Consular Relations, the Optional Protocol, and Article 94 of the U.N. Charter.

"If denying Mr. Leal the review and reconsideration of his conviction and sentence ordered by the ICJ is so important as possibly to justify the serious harm to U.S. interests identified by the president, this court, and many, many others that would follow from that treaty breach, that judgment should be made by the U.S. Congress, not Texas," the petition said.

"The United States' word should not be so carelessly broken, nor its standing in the international community so needlessly compromised," Leal's attorneys said.

The U.S. Supreme Court ruled in 2008 against Jose Humberto Medellin, a Mexican national who was executed in Aug. 5 of that year, rejecting his attorneys' argument that his right to consular assistance under the Vienna Convention's Article 36 had been violated.

In Medellin's case, the high court ruled that the treaty had to be enacted into law by Congress before it could be binding upon state courts.

The difference in Leal's case as opposed to that of Medellin is that legislation has now been introduced in Congress that has the administration's full support, the attorneys argued in the petition.

Leal's defense team has filed a separate petition with the Texas Board of Pardons and Paroles; backed by former U.S. diplomats and retired military brass, it also calls for a temporary stay of the Mexican man's execution.

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