Aversion to the punishment will outweigh abhorrence at McVeigh's crime when the Oklahoma City bomber pays with his life for an atrocity that killed 168 people.
"All killing, be it state execution or terrorism, is morally reprehensible and the state has no right to start along the path of revenge," said Javier Barrera, parliamentary justice spokesman for Spain's opposition Socialist Party.
Plans to broadcast the execution in Terre Haute, Indiana, on closed-circuit television to some 300 relatives and survivors have alienated even supporters of capital punishment in the European Union, where the death penalty is banned.
"The execution of McVeigh is a typical example of an execution which is justifiable in view of the crime," said Menno de Bruyne, a spokesman for the small National Reformed Party party in The Netherlands. "However, we do not approve when it is made into some kind of a show."
McVeigh is scheduled to die by lethal injection on May 16 for bombing the Alfred P. Murrah federal building in Oklahoma City on April 19, 1995 in the worst act of domestic terrorism in U.S. history.
It will be the first federal execution since 1963.
Concern in Europe over use of the death penalty in the United States has grown with the election of Republican President Bush, who presided over more than 150 executions during his almost six years as Texas governor.
His administration has dismissed a plea from Pope John Paul II to spare McVeigh's life.
"I think if there was ever a man who deserves to be executed it's probably Timothy McVeigh," Vice President Dick Cheney told Fox News last month.
Pitted against that is a view in Europe that holds capital punishment is cruel and brutalizing, leaves no room for judicial error, may increase rather than deter violence and, in a case like McVeigh's, risks making a martyr of a criminal.
"I am still in contact with several relatives of McVeigh's victims, and while I can understand why they might want to bear witness to his death, a greater revenge would surely be to let him vanish into the anonymous nothingness he deserves," wrote journalist Ben Macintyre of the Times of London.
"I would far rather see McVeigh expire in prison, old, rotten and forgotten. He is a hopeless failure who craved attention, and now he is getting it, in spades."
McVeigh, 33, a Gulf War Veteran, has expressed no remorse for the bombing and passed up a chance to seek clemency earlier this year because he did not expect to win a pardon and did not want to spend the rest of his life in prison.
In a recent book, "American Terrorist," McVeigh was quoted as saying he detonated the fertilizer truck bomb to avenge the government siege of the Branch Davidian compound in Waco, Texas that ended in the deaths of more than 80 Davidians.
"Timothy McVeigh is considered by many a textbook example of why the death penalty is justified," the Londo-based human rights group Amnesty International said.
"However, evidence shows that rather than deterring crime the death penalty may actually increase violence in society."
All EU governments oppose the death penalty and are pushing for its abolition worldwide. They are expected to protest McVeigh's execution through their embassies in Washington, according to the bloc's Swedish presidency.
The last person to be executed in the 15-nation grouping, Hamida Djandoubi, was guillotined in France in 1977, one year after the U.S. Supreme Court reinstated the death penalty.
More than 700 inmates have since been executed in the United States, most with little fanfare, in the 38 states that have capital punishment. McVeigh's execution will leave 19 other prisoners on federal death row awaiting their fates.
"After a 38-year de facto moratorium on executions of federal prisoners, the McVeigh case shows a new course that justifies the concerns of human rights campaigners," said Rudolf Bindig, a human rights expert for Germany's ruling Social Democratic party.
"A lot has been spoken about a trans-Atlantic community of shared values but it seems our values are drifting further from each other," he said. "The death penalty is one of those fields."