Sanders campaign accused of accessing Clinton data

WASHINGTON (Reuters) - The campaign of Democratic presidential candidate Bernie Sanders was accused of breaching voter data from rival Hillary Clinton's campaign, adding intrigue to a debate featuring the two this weekend.

The breach of Democratic National Committee files led to the firing of a top Sanders data staffer and prompted the DNC to cut off the Sanders campaign's access to its voter data.

The incident comes at an inauspicious time for Sanders, the Democratic socialist who is trying to stop the heavily favored Clinton from running away with the party's 2016 presidential nomination. Sanders has been lagging behind Clinton, with 29 percent support to her 60 percent in recent Reuters/Ipsos polling.

Sanders, Clinton and a third candidate, former Maryland Governor Martin O'Malley, are to meet for a debate at St. Anselm College in Manchester, New Hampshire, on Saturday night.

The Sanders campaign scheduled a news conference to address the controversy at 1 p.m. EST (1800 GMT) on Friday at his Washington campaign headquarters.

The breach occurred for a brief period on Wednesday when staff at Sanders' campaign were able to view confidential information from the Democratic National Committee, the DNC said.

In a statement on Friday, the Sanders' campaign said the breach of the files, which contain voter information such as past support and donation history, was an isolated incident and blamed it on the DNC's software vendor, Washington-based NGP VAN, media reports said.

The campaign blamed it on an "incompetent vendor who on more than one occasion has dropped the firewall between the various Democratic candidates' data."

Stu Trevelyan, chief executive of DNC software vendor NGP VAN, acknowledged the breach in a statement but said his company is not aware of any previous reported incidents of data being "inappropriately available." He called the breach a "brief isolated issue" that was fixed and is now being reviewed.

A liberal group, Democracy for America, rushed to Sanders' defense.

"The Democratic National Committee's decision to attack the campaign that figured out the problem, rather than go after the vendor that made the mistake, is profoundly damaging to the party's Democratic process," said Charles Chamberlain, Democracy for America's executive director.

He said DNC leaders "should immediately reverse this disturbing decision before the committee does even more to bring its neutrality in the race for president into question."

Many liberals have concerns that the DNC has made decisions aimed at helping Clinton become the nominee, such as staging fewer debates and holding them on weekends when fewer people will be watching.

A person familiar with the matter told CNN that Josh Uretsky, the Sanders campaign's national data director, was fired for accessing the voter data.

Uretsky, who could not be reached immediately by Reuters for comment, told CNN he was not trying to take data from Clinton's operation but that he knew there was a security problem and wanted to determine the vulnerability of his candidate's own data.

The DNC said that at its request, NGP VAN suspended the Sanders campaign's access to DNC files but said it would be restored once a full accounting has been given and the problem fixed.

The Washington Post first reported the data breach late on Thursday, citing several party officials.

Sanders' campaign told NBC none of the accessed data had been downloaded or printed.

CBS News cited a Democratic election source as saying the Sanders campaign will have to explain its actions and provide proof that the data obtained during the breach has been disposed of in order to regain access to DNC files.

"We are also looking at the option of an independent audit by a data security firm," the source said.

(Reporting by Susan Heavey and Megan Cassella in Washington and Luciana Lopez and Emily Flitter in New York; Writing by Steve Holland; Editing by Bill Trott)