With the backing of former judges, prosecutors and diplomats from across the country, lawyers are asking Texas Gov. Rick Perry and other state officials to delay the scheduled July 7 execution of Humberto Leal Garcia. The case echoes the dispute involved in the 2008 Supreme Court decision in Medellin v. Texas, and also implicates pending action in Congress.

Leal is a Mexican national arrested in 1994 on suspicion of murder who was never told that he had a right under an international treaty to contact the Mexican consulate for legal assistance. It was not until he was on death row that a fellow inmate gave him the address of the Mexican consulate.

Without the legal assistance he might have gotten through the Mexican government, Leal received “disgracefully inadequate legal representation,” acccording to the clemency petition, and was convicted on “junk science” evidence that has since been discredited. At his sentencing hearing, Leal’s lawyers failed to present any mitigating evidence including his mental disabilities, brain damage and sexual abuse as a child. “He never stood a chance,” said Northwestern University School of Law professor Sandra Babcock, Leal’s current attorney and author of the petition sent to the Texas Board of Pardons and Paroles Tuesday.

But the broader issue in Leal’s case — his rights under the Vienna Convention on Consular Relations — is what attracted the nationwide coalition of supporters. If Leal is executed without any examination of the unfairness of his failure to be notified of his consular rights, they argue, then foreign governments may retaliate and not honor the consular rights of U.S. citizens arrested in other countries.

Because foreign nationals may be unfamiliar with the U.S. legal system or unable to secure adequate representation, receiving the help of a consulate “can mean the difference between conviction and acquittal, or between life and death,” said the group of former judges and prosecutors in a letter to Perry and the pardons board. “It is appropriate to ensure that our country complies with the laws to which it has obligated itself, and to ensure that those laws apply to our own citizens as well.” Among those signing this statement were former FBI director and district court Judge William Sessions, former federal appeals Judges Shirley Hufstedler, John Gibbons and Nathaniel Jones, and former Texas Attorney General and Gov. Mark White.

“We cannot realistically expect other nations to continue to comply with consular treaty commitments that we refuse to uphold,” added a group of former diplomats led by John Bellinger III, former Bush administration legal adviser for the State Department, now a partner at Arnold & Porter. The letter cites the 2009 detention of three Americans who strayed into Iran. In that incident, American officials demanded that Iran comply with the requirements of the consular treaty, and consular access was granted.

The letters ask Texas to stay the execution until Congress can finally act in response to the Supreme Court’s Medellin ruling, which dealt with the consular treaty’s impact when states ignore its requirements. Leal, like Jose Ernesto Medellin, the defendant in the Supreme Court case, was part of a group of 51 Mexican nationals who had challenged state violations of the treaty before the International Court of Justice. That court ruled that their cases should be reviewed and reconsidered in state courts because of the treaty violation. Texas courts refused, and the Supreme Court said the treaty was not directly binding on state courts unless Congress acted to implement it.

A bill is expected to be introduced soon in the Senate — with the backing of the State Department and Justice Department — that would provide for court hearings to review the cases of foreign nationals whose consular rights were violated.

Babcock said the congressional response has momentum, after years of delay caused by related and unrelated reasons. “Here we are, the most powerful country in the world, and we can’t figure out how to comply with the law.” She also said the Leal case poses a starker example of the importance of the consular rights treaty than the Medellin case did, because having competent counsel through the Mexican government clearly would have made a difference for Leal. “This would not have been a capital case. It was a defensible case,” she said, because of the flawed evidence introduced at trial and the failure of counsel to assert mitigating factors at sentencing.

More broadly, she said the consular issue, once it is explained, gains wide support because of the possible repercussions for U.S. citizens if the U.S. does not honor the treaty. “Everybody’s got a kid who has been a foreign exchange student, or knows someone who has been on a mission abroad,” she said. “The issue has legs.”

This article first appeared on The BLT: The Blog of Legal Times.