The impending execution in Texas of a Mexican citizen has civil rights organizations up in arms, as well as a renewed call from Mexico for better legal services and access to diplomatic rights for their citizens who are detained in the United States, and Texas in particular.

Edgar Arias Tamayo, 46, is scheduled to be executed on Jan. 22 as a result of a conviction for the murder of a Houston police officer in 1994. However, as has been noted by many judicial watches, Tamayo was not notified of his right to access Mexican consular services when he was arrested, and the Mexican authorities were not aware of his arrest and detention until one week before his trial.

His case is one of more than 50 which was brought to the attention of the International Court of Justice (ICJ) in The Hague. Mexico sought the courts assistance on behalf of Mexican citizens jailed in the U.S. who had not been afforded their rights under the Vienna Convention on Consular Relations of 24 April 1963.

The court found in Mexico's favor on six points, noted the U.S. agreement and participation in the convention and ordered the U.S. "shall provide, by means of its own choosing, review and reconsideration of the conviction and sentence, so as to allow full weight to be given to the violation of the rights set forth in the Convention, taking account of paragraphs 138 to 141 of this Judgment."

According to the Ministry of Foreign Affairs in Mexico, that review is still pending, and Foreign Secretary José Antonio Meade has requested a stay of execution on that basis.

Tamayo's case has already produced a torrent of legal wrangling and letter writing up to this point. The international human rights watchdog group Amnesty International is among those calling out Texas for apparently violating an international order to stop the execution of certain named defendants in the U.S.

 "A Mexican national who had come to the USA as a 19-year-old to find work, Edgar Tamayo had the right to seek consular assistance 'without delay' after arrest, as required under article 36 of the Vienna Convention on Consular Relations (VCCR)," writes Amnesty International. "He was not advised of this right and the Mexican authorities did not learn of the case until a week before the trial. Without access to the sort of assistance the consulate has since provided for appeals, Edgar Tamayo's trial lawyer failed to present evidence of the deprivations and abuse his client suffered as a child, his developmental problems, a serious head injury he sustained when he was 17 and its impact on his behaviour, including a worsening dependency on drugs and alcohol. In 2008 a psychologist put Edgar Tamayo's intellectual functioning in the "mild mental retardation" range, which would render his execution unconstitutional under US law."

Additionally, U.S. Secretary of State John Kerry has written a letter to Texas governor Rick Perry requesting that the sentence be delayed. Kerry acknowledges the seriousness of the crime for which Tamayo has been convicted, but characterizes his request as a "process issue."

"I have no reason to doubt the facts of Mr. Tamayo's conviction, and as a former prosecutor, I have no sympathy for anyone who would murder a police officer," Mr. Kerry wrote according to a NY Times report. "Our consular visits help ensure U.S. citizens detained overseas have access to food and appropriate medical care, if needed, as well as access to legal representation."

As noted by the Mexican Ministry of Foreign Affairs, Tamayo's execution would be the third execution carried out by Texas against Mexican individuals named in the ICJ cause since the international court handed down its decision.

Jose Ernesto Medellin and Humberto Leal Garcia were executed in 2008 and 2011. Medellin was convicted in the 1993 murder of two teenage girls in Houston. Garcia was convicted in the rape and murder of a teenage girl in San Antonio in 1994.

The Mexican news site Proceso notes that Since 1976 , Texas has killed nearly 500 people and 289 currently sit on death row. During the administration of Gov. Perry , who has served since December 2000, 269 people have been executed . In 18 states there is no death penalty, and in another 29 it has not been practiced in the past five years.