In separate letters sent Tuesday to Interior Secretary Dirk Kempthorne, 113 scientists and 23 lawmakers said the draft plan to protect the northern spotted owl distorted scientific studies to justify logging in old-growth forests, and alleged that it had been "politicized" by Interior Department officials.

"There's very clear evidence that this recovery plan was polluted by tainted politics," Jay Inslee, a Democratic lawmaker from Washington, one of three states concerned by the plan, told AFP.

The lawmakers' letter, part of which was posted on Inslee's website, said: "The recovery plan may have been tampered with by high-ranking officials within the administration, including former Interior Department Deputy Assistant Secretary Julie MacDonald who... was a member of the Washington Oversight Committee' that apparently instructed the recovery team to develop options not based on sound science."

The recovery plan, drawn up by the Interior Department's Fish and Wildlife Service, minimizes the need to preserve the forest ecosystem in California, Oregon and Washington, in which the spotted owl lives -- despite mentioning that the owl was listed as a threatened species in 1990 "because of widespread loss and adverse modification of suitable habitat."

In a separate letter to Kempthorne, independent scientists expressed concern that the plan had largely ignored scientific findings.

"We are greatly concerned that, according to scientific peer review recently conducted by owl experts and three of the nation's leading scientific societies, much of this science was ignored in the draft recovery plan for the northern spotted owl," the scientists' letter said.

"Based on our understanding of the ecology of the spotted owl, we see no scientific basis for reducing habitat protections for the owl," it said.