NEW YORK, April 30 -- A poster campaign opposing Amazon founder Jeff Bezos's involvement in the upcoming Met Gala cropped up across New York's streets and subways yesterday, calling for a boycott of the star-studded event.

Bezos and his wife Lauren Sanchez Bezos are lead sponsors and honorary co-chairs of the high-profile fundraising event, to be held May 4, which draws A-listers across entertainment, sport, fashion and business.

But the billionaire couple's stake in the gala has angered activists, who primarily oppose Bezos's business practices.

One poster depicts a bottle filled with urine on a red carpet - a reference to some Amazon drivers having to urinate in bottles due to a lack of bathroom breaks.

Another portrays Bezos in a U...