An international trade union has asked ship operators handling goods in Walmart‘s global supply chain to raise concerns with the company about how it treats its US workforce.

Walmart has been affected by a series of walkouts and protests by several union-supported groups seeking to highlight what they say are low pay, poor benefits and retaliatory measures against those employees who speak out.

A series of high-profile protests are now planned to highlight “Black Friday” this week, which is the busiest single shopping day in the US calendar.

Organisers behind the OUR Walmart and Making Change at Walmartgroups say up to 1,000 actions are planned and several walkouts have already happened.

Now the International Transport Workers’ Federation (ITF) has written to shipping owners and ship captains who carry Walmart goods and asked them to contact the gigantic global company and express support for the protesting workers. “Walmart workers taking industrial action know that their jobs are at risk. The least we can do to help is use our expertise at sea and relations with the shipping industry to back them in any way we can.”