A top US justice department official who refused to testify before Congress about her role in the sacking of eight federal prosecutors has resigned.
Ms Goodling is a key aide of the embattled US attorney general
Monica Goodling, who was senior counsel to Attorney General Alberto Gonzales, gave no reason for her abrupt decision.
Last month she rejected an interview request from a congressional committee investigating the sackings, invoking her right not to incriminate herself.
Mr Gonzales denies the sackings last year were politically motivated.
The Democratic Party, which now controls Congress, is pushing to expand an investigation into the firings, which affected almost one in 10 federal prosecutors.
Mr Gonzales - who heads the justice department - says the attorneys were fired because of their job performance and that politics played no role.
Serve at the discretion of the president, with the approval of the Senate
Prosecute criminal cases brought by the government
Prosecute or defend civil cases in which the government is a party
Collect debts owed to the government
Source: US Department of Justice
But critics says they were meant to halt investigations into Republican officials or punish the attorneys for failing to prosecute Democrats.
Ms Goodling, who submitted her resignation to Mr Gonzales in a brief three-sentence letter, served as the Justice Department's liaison with the White House.
Last month, a Senate committee voted to authorise legal orders compelling key White House aides to testify in the case, but President Bush has vowed to resist this.
Mr Gonzales, who faces calls to resign, is likely to testify before Congress later this month.