Workers are refusing to unload Russian oil from a German-flagged ship, which is moored at a major British oil refinery, Report informs referring to the BBC.
The Seacod vessel is berthed near the Stanlow Oil Refinery in Cheshire.
The UK government has banned ships with "any Russian connection" from entering its ports due to the country's invasion of Ukraine.
However, the Unite union said cargo was not included in the ban and has called for ministers "to close this loophole".
Sharon Graham, general secretary of Unite, said they had informed the company that "Unite workers at the facility will under no circumstances unload any Russian oil regardless of the nationality of the vessel which delivers it."