Passengers arriving from overseas will be fuming about new duty-free tobacco restrictions that come into effect tomorrow.

Airports have warned inbound passengers can expect long delays in customs halls around the country as officials attempt to enforce a new cigarette limit of two packs per adult, down from the current limit of 250 cigarettes or 250 grams of tobacco products.

The Federal Government has cut the duty-free allowance to 50 cigarettes (effectively two packs) from September 1, and any brought into the country from tomorrow over the limit have to be declared for payment of federal duties or be surrendered.

The Australian Airports Association, representing the nation's airports, has slammed the rushed implementation of the new duty-free allowance, saying it will divert already-stretched customs officers from the front line of passenger processing.

Officers will be patrolling passenger queues to request passengers to surrender cartons of duty free cigarettes over the two-pack limit or pay the tobacco duty due, the association said.