WASHINGTON (AP) – Eight federal prosecutors were fired last year because they did not sufficiently support President Bush’s priorities, Attorney General Alberto Gonzales’ former chief of staff maintains, calling it a legitimate policy.

Kyle Sampson, who quit earlier this month over the furor, disputed Democratic charges that the firings were a purge by intimidation and a warning to the remaining prosecutors to fall in line. Nor, he said, were the prosecutors dismissed to interfere with corruption investigations.

“To my knowledge, nothing of the sort occurred here,” Sampson said in remarks prepared for delivery Thursday before the Senate Judiciary Committee.

Democrats viewed his testimony as key to finding the answers to the political question and a second, investigative query: Did Mr. Gonzales and the Justice Department provide misleading accounts of the run-up to the firings?

The answer to the second question is yes, according to a Justice Department letter accompanying new documents released hours before Mr. Sampson’s appearance.

The Justice Department admitted Wednesday that it gave senators inaccurate information about the firings and presidential political adviser Karl Rove’s role in trying to secure a Federal prosecutors post in Arkansas for one of his former aides, Tim Griffin. Acting Assistant Attorney General Richard Hertling said that certain statements in last month’s letter to Democratic lawmakers appeared to be “contradicted by department documents included in our production.”

That admission, only hours before Mr. Sampson’s testimony, took some of the sting out of Democrats’ key pieces of evidence that the administration had misled Congress.

Still, Mr. Sampson provided plenty of fodder. He acknowledged planning the firings as much as two years ago with the considered, collective judgment of a number of senior Justice Department officials.

However, he denied that the firings were improper, and he spoke dismissively of Democrats’ condemnation of what they call political pressure in the firings.

“The distinction between ‘political’ and ‘performance-related’ reasons for removing a United States attorney is, in my view, largely artificial,” he said. “A U.S. attorney who is unsuccessful from a political perspective … is unsuccessful.”

Mr. Sampson maintained that adherence to the priorities of the president and attorney general was a legitimate standard.

“Presidential appointees are judged not only on their professional skills but also their management abilities, their relationships with law enforcement and other governmental leaders and their support for the priorities of the president and the attorney general,” he said.

Mr. Sampson strongly denied Democrats’ allegations that some of the prosecutors were dismissed for pursuing Republicans too much and Democrats not enough in corruption cases.

“To my knowledge, nothing of the sort occurred here,” he said.

The White House said it will withhold comment on Mr. Sampson’s testimony until he actually testifies.

The Feb. 23 letter, which was written by Mr. Sampson but signed by Mr. Hertling, emphatically stated that “the department is not aware of Karl Rove playing any role in the decision to appoint Mr. Griffin.” It also said that “the Department of Justice is not aware of anyone lobbying, either inside or outside of the administration, for Mr. Griffin’s appointment.”

Those assertions are contradicted by e-mails from Mr. Sampson to White House aide Christopher G. Oprison on Dec. 19, 2006, about a strategy to deal with senators’ opposition to Mr. Griffin’s appointment. In the e-mail, Mr. Sampson says there is a risk that senators might balk and repeal the attorney general’s newly won broader authority to appoint Federal prosecutors.

“I’m not 100 percent sure that Tim was the guy on which to test drive this authority, but know that getting him appointed was important to Harriet, Karl, etc,” Mr. Sampson wrote. Former White House Counsel Harriet Miers was among the first people to suggest Mr. Griffin as a replacement for Mr. Cummins.