WASHINGTON, (AFP) - A Texas death row inmate who appealed his conviction on the grounds that the judge in the case was having an affair with the prosecutor saw his appeal rejected late Monday on procedural grounds, opening the way for his execution on Tuesday.

The state criminal appeals court rejected the appeal of Charles Hood, 38, sentenced to death in 1990 for two murders, saying that the claim about the judge was not "new" information available to the case.

It said the information could have been included in earlier appeals made by Hood's lawyers, but was not; and that his lawyers offered no evidence that it made a difference in the jury finding Hood guilty.

The court also rejected the petition to stay his execution on grounds that the wrong attorney signed the petition.

The rejection leaves Hood's attorneys few routes of appeal to block his execution scheduled for 6:00 pm (2300 GMT) Tuesday at the prison in Huntsville, Texas.

Hood, was convicted and sentenced to death in 1990 for killing his supervisor and the supervisor's girlfriend the year earlier in Plano, Texas.

His fingerprints were found at the scene of the crime and he was caught fleeing in the victims' car, together with their jewelry, credit cards and other items.

Late last week, his lawyers petitioned the court to stay his execution and to nullify his conviction based on evidence that the judge in his case was in a relationship with the prosecuting attorney.

In an affidavit in the application to overturn Hood's conviction, Matthew Goeller, a former assistant district attorney, called the relationship "common knowledge."

"This relationship (...) was in existence in 1987 (...) and it continued until approximately 1993," he said.

A dozen professors of ethics and the law wrote to the court and to Texas Governor Rick Perry arguing that if the judge and the prosecutor were in a relationship at the time, Hood's conviction should be overturned.

"An impartial judge is an essential component of the American adversary system. If a judge's impartiality is subject to reasonable question, there is a 'structural defect' in the trial, meaning that vacation of the conviction is required," they wrote.