Cinema chains could refuse to show major films in a showdown with two leading studios over home viewing.
Warner Brothers and 20th Century Fox are expected to soon launch a premium online video-on-demand service, allowing people to watch movies on their TVs and computers a month after they are first screened.
Cinema companies are outraged by the proposals, which would greatly reduce the standard gap of four months between cinematic openings and films becoming legally available for the small screen. They believe it would greatly cut into profits by reducing their time window for luring audiences into cinemas and have warned that it would cause many cinemas to close down.
Their cause is supported by 23 of the world's most successful directors, including James Cameron, Kathryn Bigelow, Guillermo del Toro and Michael Mann, who attacked the plans in an open letter published in Hollywood trade magazine Variety.
Last year, the UK's three largest cinema chains announced they would refuse to screen Tim Burton's film Alice in Wonderland due to Disney's plan to release the movie on DVD a month earlier than usual.
Although Cineworld and Vue eventually relented, Odeon went through with the boycott.
James Cameron, the man behind the two biggest grossing films of all time, Avatar and Titanic, has been an outspoken critic of the plans. Leading the open letter from fellow directors, he wrote: "The cinema experience is the wellspring of our entire business, regardless of what platforms we trickle down to. If the exhibitors are worried, I'm worried. We should be listening to them."