Four dozen evangelical leaders across the US issued an open letter today seeking to stop the execution of a death row inmate scheduled to be executed on 24 August after being convicted of being an accomplice to a murderer.

The group is protesting against the impending execution in Texas of Jeff Wood, who is described as having "intellectual and emotional disabilities" and who drove a getaway car but did not use a weapon in the murder of a petrol station assitant, Kris Keeran, during a robbery on 2 January 1996.

Danny Reneau, Wood's former room-mate, was convicted of shooting Keeran in the head. Reneau was executed in 2002.

Wood, 42, was convicted under a Texas law known as the 'law of parties,' which makes him equally responsible for crimes committed by his accomplice that "should have been anticipated".

"Our faith compels us to speak out in this case, where a looming execution date threatens the life of an individual with significant mental impairments who never should have been sentenced to death," the group wrote. "Officials have a moral obligation to rectify this mistake and stop this execution while they still can...It deeply troubles us when the criminal justice system concludes that some of the most vulnerable in society can be executed and disposed of," the letter said. "All are made in God's image, and as a society we especially must protect those with mental illness and disabilities. Public officials must not shirk this responsibility. We urge them to act now to spare Wood's life."

Texans who have signed the letter include: N. Larry Baker, a professor at Logsdon Seminary at Hardin-Simmons University and one-time head of the Southern Baptist Convention Christian Life Commission; Paul Basden, co-founder and senior pastor of Preston Trail Community Church in Frisco; and Bill O'Brien, a former SBC International Mission Board administrator and Samford University professor who how serves as executive director of The Gaston Christian Center in Dallas.

National figures joining the call included the Mercer University professor David Gushee, Baptist historians Bill Leonard and Walter Shurden, and Fisher Humphreys, the emeritus professor at Samford University.

Other Baptists who signed the letter included the Baylor University professors Derek Dodson, senior lecturer in the religion department, and Ralph Wood, the university professor of theology and literature. Others who signed included LaMon Brown, a retired missionary of American Baptist Churches, USA; Valerie Burton, minister for Christian formation at Baptist Church of the Covenant in Birmingham, Alabama; Carolyn and Larry Dipboye, co-pastors of Grace Covenant Church in Oak Ridge, Tennessee; and Paul Richardson, the former treasurer and board member of the Alliance of Baptists.

Family and friends of Wood have set up a webpage – Save Jeff Wood – aimed at persuading the authorities not to carry out the execution.

Wood was due for execution in 2008 but five hours before it was scheduled, a federal judge in San Antonio issued a stay of execution to allow a hearing to determine whether he was mentally competent.