A deal between billionaire Carl Icahn and the casino workers union in Atlantic City fell apart on Sunday and now the future of the Taj Mahal casino is in doubt.

The development extends an acrimonious three-month stand-off that has threatened to close the sprawling Agra-themed casino resort, put 3,000 employees out of work and turn the casino into the ultimate white elephant on the Boardwalk.

Under the tentative deal reached last week, Icahn had given in to union demands, restoring health and pension benefits he had gone to court to revoke and giving up on attempts at outsourcing and new work rules, including increased room cleaning quotas and the elimination of paid meal breaks.