Children from poor families could be left hungry by disruptions to freight on the Spirit of Tasmania, a major food charity is warning.
Foodbank says deliveries across Bass Strait have dropped from up to 20 pallets a week to around four because of delays caused by a protest in Melbourne.
Tasmanian CEO Ed Gauden said 191 charities and 61 school breakfast programs were in danger of having their food donations cut back.
"What stock is coming through is very close to use-by date or out of date," Mr Gauden told AAP.
"I'm concerned how long this is going to keep going because it's the middle of winter."
Mr Gauden said Foodbank of Tasmania had already distributed the equivalent of 400,000 meals this year - more than it did for the whole of 2012.
Bushfires in January and Australia's highest unemployment rate had exacerbated the problem, he said.
Freight services across Bass Strait are donated to the charity by SRT Logistics, which has needed to prioritise paying customers.
Mr Gauden is calling on Tasmanian producers to donate nutritious food to make up for the shortfall.
"I've got other types of food here that can go out but we need the nutritious food, healthy food, what's needed on the table rather than the biscuits and the chocolates.
"It's kids that are not going to get fed proper meals."
Protesters have returned to Station Pier in Melbourne, despite a court injunction banning the picket.
They had earlier attempted to blockade cargo access in protest at staff sackings safety concerns at stevedoring company Qube.
Qube has accused the Maritime Union of Australia (MUA) of organising the protest, a claim the union denies.
The MUA has called for a resolution but says safety concerns need to be addressed.
Further court action is pending, but the dispute has already cost a reported $10 million in fresh produce.
Tasmanian Liberal senator Eric Abetz called on police to step in.
"If we're going to have the rule of law and a civil society then the law enforcement agencies do need to take heed and act," he said.
