LONDON (CMC):

Amnesty International is urging the US state of Florida to halt the execution of a Jamaican drug trafficker convicted for killing a state trooper with a pipe bomb.

The London-based human-rights watchdog said that Paul Howell, 47, who is due to be put to death tomorrow evening, was denied the federal review of his appeal claims after his lawyer missed a filing deadline. As a result, the Florida Supreme Court refused to stay the execution.

Howell was convicted of killing Florida Highway Patrol Trooper Jimmy Fulford in February 1992.

"While Amnesty International opposes the death penalty in all cases, even supporters of this punishment should be concerned by the questions being raised about the quality of the legal representation this capital defendant received at trial and on appeal," said Amnesty International's US researcher Rob Freer.

Howell's current lawyers continue to press for a court to block the execution "so that they can present evidence that he received poor legal representation at trial," Freer added.

Amnesty International said Howell's trial attorney had "an apparent conflict of interest".

"Then, to add insult to injury, the case was not reviewed by any federal court because a subsequent lawyer filed an appeal too late," it said.

In addition to his conviction for killing Fulford, Howell also faced separate charges under a federal drug conspiracy law.