(Las Vegas) — Mitt Romney’s campaign is blocking reporters from covering GOP vice presidential candidate Paul Ryan’s first meeting with donors in Las Vegas.

Tuesday night’s event at The Venetian hotel is expected to draw casino owner and Republican mega-donor Sheldon Adelson.

The decision to block access marks an apparent break from rules previously established by Romney’s campaign.

Reporters usually are allowed to cover President Barack Obama’s fundraisers held in public venues.

A Romney aide who was not authorized to speak for the record said the event is closed to the media because it is a “finance meeting” instead of a fundraiser. The aide said fewer than 40 people will attend, which is usually the threshold for access.