Senior White House aide Karl Rove has announced he will step down at the end of August.
Mr Rove (56), a political adviser to President George W. Bush and White House deputy chief of staff, revealed during an interview with the Wall Street Journaltoday that he will leave Washington at the end of this month.
He has held a senior post in the White House since President George W. Bush took office in January 2001.
"I just think it's time," Rove said. "There's always something that can keep you here, and as much as I'd like to be here, I've got to do this for the sake of my family."
Known as "the architect" for his campaign skills, Mr Rove is the latest in a series of senior Bush aides to resign in recent months.
Earlier this month, Mr Bush cited executive privilege to reject a subpoena for Mr Rove to appear before the Senate Judiciary Committee in an investigation over fired federal prosecutors.
The president's opponents have sought to force Mr Rove and other aides to testify about the firing last year of nine US prosecutors.
Democrats say the firings may have been intended to influence investigations of Democratic or Republican lawmakers. Mr Bush and Attorney General Alberto Gonzales, who signed off on the firings, have said they were justified but mishandled.
Mr Gonzales also faces calls for a perjury investigation over the truthfulness of his testimony to Congress about the firings and a warrantless domestic spying programme.
The Journalsaid Mr Rove had first put out the idea of resigning a year ago, but delayed leaving as the Democrats won control of Congress late last year and then as the White House faced debates about immigration and the Iraq war.
Mr Rove finally decided to leave after Joshua Bolten, the White House chief of staff, told senior aides that if they remained past early September, they would be obliged to stay until the end of Mr Bush's second and final term in January 2009, the paper said.
Mr Rove, who was chief strategist of Bush's presidential campaign in 2000, has had a senior post in the White House since Bush took office in January 2001.
The Journalsaid Rove was planning to return to Texas, as he and his wife have a home in Ingram and a son attending college in San Antonio.