Anne Hathaway walks off Vanity Fair photo shoot after SAG-AFTRA joins one-day Condé Nast picket line

Anne Hathaway was scheduled to shoot a Vanity Fair cover on the same day as a walkout by unionized staffers.Getty Images for National Board of Review

Anne Hathaway walked out of a Vanity Fair cover shoot on Tuesday, sources tell Page Six — when members of her union, SAG-AFTRA, joined a one-day walk out in solidarity with unionized Condé Nast staffers.

Sources told Page Six that “The Devil Wears Prada” star arrived at the shoot in New York on Tuesday morning, and was in hair and makeup when she pulled the plug on the photo session.

We hear that the VF shoot was not violating any union guidelines, and that Hathaway and her team had done their due diligence and were initially OK’d for the shoot.

But when members of actors union SAG-AFTRA joined Condé Nast picketers outside the publisher’s One World Trade Center HQ during the work stoppage, Hathaway was contacted again by SAG and backed out.

A source said that it was not a dramatic exit, but we hear that the move caused some confusion.

The “Devil Wears Prada” star was in hair and makeup, but left the Vanity Fair session. GC Images

Said one insider familiar with the shoot, “people were like, ‘WTF is happening?’” Word spread at the studio that Hathaway walked off the shoot “because of something to do with SAG and the Condé Nast strike.”

About 400 unionized staffers at Condé Nast mags including Vogue, GQ and VF walked off the job on Tuesday and picketed at One World Trade Center. They’re alleging “unlawful bargaining tactics” after Condé Nast announced it would lay off about 5% of its staff.

Last week, the company folded its hipster music site Pitchfork into GQ to cut costs.

Conde Nast staffers were picketing at the media giant’s NYC headquarters. AFP via Getty Images

An insider said of the Hathaway shoot, “great care was taken to make sure it didn’t violate union rules,” and, “everything was above board.”

Hathaway was hailed as a hero by the striking workers after she made an about-face on the shoot.

SAG recently wrapped up its own bruising Hollywood work stoppage.

SAG-AFTRA was supporting the Conde Nast strike. sagaftra/Instagram

After Hathaway walked, SAG-AFTRA posted a social media statement its national exec director Duncan Crabtree-Ireland that said, “Condé Nast workers have the backing of SAG-AFTRA… We applaud these workers taking action to defend their livelihoods, and we encourage everyone to recognize the Condé Nast picket line and join us in supporting this promising new era of worker empowerment.”

The shoot is now being rescheduled for another day, we hear.

Reps did not comment.

We hear that the VF shoot is being rescheduled. WireImage for British Fashion Council The media company said it will lay off 5% of its staff. AFP via Getty Images

Hathaway also appeared this month as a guest star on Broadway for one night with Condé Nast big Anna Wintour in “Gutenberg! The Musical!” we previously reported.