A government watchdog group that has long fought for increased transparency is siding with President Barack Obama’s use of executive privilege to shield documents sought by House Republicans’ “Fast and Furious” gun-walking probe.

The move is likely to be cited by Democrats who say Republicans are abusing their power in moving to hold Attorney General Eric Holder in contempt of Congress for refusing to provide the documents.

But it could also give ammunition to GOP critics of the group who have alleged it has a partisan bias.

Melanie Sloan, executive director of Citizens for Responsibility and Ethics in Washington, said she is supporting Obama’s decision to shield the documents via executive privilege because she became convinced the GOP investigation was basely political.

“Fast and Furious was a disaster and Attorney General Holder and the Justice Department should answer for it,” Sloan said. “But the records Republicans are howling about — which have nothing at all to do with the operation — won’t shed any light on how it all went so wrong. This isn’t about transparency; it’s about politics and the upcoming elections.”

House Oversight and Government Reform Chairman Darrell Issa (R-Calif.) has focused on a specific category of documents in the standoff with Holder over contempt.

The documents are internal Justice Department communications in the months after the department broadly — and falsely — denied that the tactics at the heart of the Fast and Furious were ever used in a February 2011 letter.

In December 2011, the department rescinded that letter and acknowledged the operation was “fundamentally flawed.”

Sloan said those documents won’t shed any light on any wrongdoing from the actual operation because the communications took place after it was shut down.

But Issa has argued the documents are key to understanding who in the Justice Department authorized or knew about the tactics, including who was surprised when it turned out that, contrary to the department’s denial, the tactics had, in fact, been used.

Frederick Hill, a spokesman for Issa, dismissed CREW’s stance.

“Have you ever seen better proof that CREW is an organization of partisan liberals who just can’t help themselves?” Hill asked.