WASHINGTON (Reuters) - A growing controversy over Democrat Hillary Clinton's use of personal email for work while she was U.S. secretary of state could drag on for months, threatening to cloud the expected launch of her 2016 presidential campaign.
Clinton tried to cool the brewing firestorm late on Wednesday, saying she wanted the State Department to release the emails quickly. But a senior State Department official told Reuters on Thursday the task would take time.
"The review is likely to take several months given the sheer volume of the document set," the official said.
That could dash any Clinton hopes of putting the controversy to rest quickly, and give her Republican foes plenty of time to hit her with allegations that the use of personal email for official duties while secretary of state from 2009 to 2013 was inappropriate.
"I want the public to see my email," Clinton said in a tweet. "I asked State to release them. They said they will review them for release as soon as possible."
The controversy landed Clinton in trouble just as she prepares to launch a bid for the Democratic presidential nomination in 2016. It has prompted some Democrats to wonder whether someone else should be their candidate in the bid to succeed President Barack Obama.
A total of 55,000 pages of documents covering the time Clinton was in office has been turned over, according to the State Department. But Clinton and her aides controlled that process, and the emails were not archived on government servers.
Secretary of State John Kerry told reporters during a visit to Saudi Arabia that the State Department would review the documents "as rapidly as possible."
"We'll conclude it as soon as we can and get those released publicly," Kerry said.
Clinton's tweeted statement came hours after a congressional committee investigating the Sept. 11, 2012, attack on a U.S. diplomatic facility in Benghazi, Libya, issued subpoenas for her emails.
The U.S. House of Representatives Select Committee on Benghazi demanded all Clinton communications related to the incident, in which a U.S. ambassador was killed, and sent letters to internet companies telling them to protect relevant documents.
The panel's Republican chairman, Representative Trey Gowdy of South Carolina, told reporters he wanted the documents within two weeks or a "really good explanation" for why not.
Republicans have scrutinized Clinton's actions regarding the Benghazi attack in which Ambassador Chris Stevens and three others were killed during an assault on a U.S. facility. Republican lawmakers believe she did not do enough to ensure the safety of Americans in Libya.
The email controversy could intensify long-standing Republican criticism of Clinton's transparency and ethics. The former first lady and U.S. senator has been a lightning rod for Republican critics dating back to the administration of her husband, former President Bill Clinton.
Clinton is the prohibitive favorite for the 2016 Democratic presidential nomination, and there was no sign the controversy was forcing a change of plans. A Democratic source familiar with campaign planning said to expect a Clinton announcement on her intentions in the spring.
The State Department has defended Clinton, saying there was no prohibition at the time on using personal email for official business as long as it was preserved.
But experts have called her use of personal email highly unusual and said it could have left her communications vulnerable to hacking.
On Thursday, the Republican National Committee's top lawyer asked the State Department's inspector general to investigate Clinton's email use.
"The American public deserves to know whether one of its top-ranking public official’s actions violated federal law," RNC Chief Counsel John Phillippe wrote in a letter urging the probe.
Additional reporting by Susan Cornwell and Amanda Becker; Writing by John Whitesides; Editing by Leslie Adler