NEW YORK >> East Coast and Gulf Coast dockworkers began a strike today, their first large-scale stoppage in nearly 50 years, halting the flow of about half the nation’s ocean shipping after negotiations for a new labor contract broke down over wages.

The strike blocks everything from food to automobile shipments across dozens of ports from Maine to Texas, in a disruption analysts warned will cost the economy billions of dollars a day, threaten jobs and potentially stoke inflation.

The International Longshoremen’s Association union, which represents 45,000 port workers, had been negotiating with the United States Maritime Alliance (USMX) employer group for a new six-year contract ahead of a midnight Monday deadline.

The ILA said in a statement today it shut down all ports from Maine to Texas at 12:01 a.m. ET (0401 GMT) after rejecting USMX’s final proposal, adding the offer fell “far short of the demands of its members to ratify a new contract”.

The ILA’s leader, Harold Daggett, has said employers such as container ship operator Maersk and its APM Terminals North America have not offered appropriate pay increases or agreed to demands to stop port automation projects that threaten jobs.

“We are prepared to fight as long as necessary, to stay out on strike for whatever period of time it takes, to get the wages and protections against automation our ILA members deserve,” Daggett said today.

The USMX said in a statement on Monday it had offered to hike wages by nearly 50%, up from a prior proposal. Daggett, meanwhile, said the union is pushing for a 61.5% pay increase, according to CNBC.

USMX did not immediately respond to requests for comment.

Hundreds of dockworkers demonstrated today at the Port of New York and New Jersey, one of the largest ports affected, carrying signs and shouting slogans as music blared and vendors hawked food. Daggett arrived to rally them with cheers of “ILA all the way!”

“Everything that comes in this country comes from the containers off these ships that my men work. And I want the world to know it. Don’t come after us saying we’re greedy. Go after those greedy bastards that own these companies in Europe,” Daggett told reporters.

The strike, the ILA’s first major stoppage since 1977, is worrying businesses that rely on ocean shipping to export their wares or secure crucial imports. It affects 36 ports – including New York, Baltimore and Houston – that handle a range of containerized goods from bananas to clothing to cars.

The walkout could cost the American economy roughly $5 billion a day, JP Morgan analysts estimate, as shipments are disrupted from busy terminals.

French shipping group CMA CGM, the world’s third-largest container shipper, today issued a force majeure notice over the strike, and said it may charge additional shipping fees for delayed vessels.

The National Retail Federation today called on President Joe Biden’s administration to use its federal authority to halt the strike, saying the walkout could have “devastating consequences” for the economy.

U.S. Representative Sam Graves, a Republican who chairs the House of Representatives’ Transportation Committee, also called on Biden “to immediately intervene to avoid this unnecessary harm to our economy.”

Biden officials have repeatedly said he will not do so, while urging both sides to come to an agreement.

The dispute is wedging labor-friendly Democrat Biden into a virtual no-win position, with Vice President Kamala Harris in a razor-thin race for the White House with Republican former President Donald Trump.

White House Chief of Staff Jeff Zients and top economic adviser Lael Brainard urged USMX board members at a meeting on Monday to resolve the dispute fairly and quickly, a White House official said.

The White House today said in a statement it is monitoring the effects on the supply chain and assessing ways to address potential impacts, noting the initial effect on consumers is expected to be limited.

Officials told Reuters on condition of anonymity they are hoping for a short strike, noting the two sides had resumed talks late on Sunday and had narrowed their differences.

The U.S. Department of Agriculture said today that it does not expect significant changes to food prices or availability in the near term.

BACKUP PLANS

Retailers accounting for about half of all container shipping volume, along with other shippers, have been busily implementing backup plans as they head into their all-important winter holiday sales season.

Many of the big players rushed in Halloween and Christmas merchandise early to avoid any strike-related disruptions, incurring extra costs to ship and store those goods.

Retail behemoth Walmart, the largest U.S. container shipper, and membership warehouse club operator Costco say they are doing everything they can to mitigate any impact.

New York Governor Kathy Hochul said the state expects no immediate impact on food supplies or essential goods but said impacts could widen depending on how long it lasts.

“It’s critical for USMX and the ILA to reach a fair agreement soon that respects workers and ensures a flow of commerce through our ports,” she said today.

In Copenhagen, Maersk shares dropped almost 5% today, with profit-taking following recent gains, as investors had been expecting significant increases in freight rates due to the strike, which would boost shipping companies’ earnings.

The Danish company has said it would introduce a port disruption surcharge on all cargo moving to and from the U.S. East Coast and Gulf Coast terminals beginning Oct. 21 ranging from $1,500 to $3,780 a container.