Major manufacturers are warning the gas shortage is crippling the industry and have called for urgent action to divert gas to the domestic market.

"Shortages of gas in the east coast market is a cruel and unfair blow to an Australian manufacturing industry," said Australian Advanced Manufacturers Council chief executive Mark Goodsell.

"Those that use gas for energy or for feedstock are all caught in this black comedy that is our energy market and our attempts to bring sense to it."

The comments come as a report from the competition regulator forecast a shortfall of between 55 petajoules and 108 petajoules.