A union chief said "under no circumstances" would workers unload Russian oil from a tanker docked at Tranmere terminal this afternoon.
The vessel, Seacod, was able to dock in the UK thanks to a loophole in government sanctions that allows Russian cargo to enter British ports as long as the vessel is not owned, operated or chartered by Russians.
Seacod sails under a German flag but collected the oil in the Russian port of Primorsk, where 30% of Russian oil exports are loaded onto ships.
READ MORE : Russians 'shot 33 unarmed civilians in my town' says Ukrainian sailor in Liverpool
It left Primorsk on February 22 and arrived in Tranmere yesterday at around 11.36am, with its cargo due for Stanlow oil refinery in Ellesmere Port, owned by Essar Oil (UK) Ltd.
Now Unite, which represents workers at Stanlow, will follow in the footsteps of other dockworkers in Kent who refused to unload a ship containing Russian liquefied gas yesterday.
Sharon Graham, general secretary of Unite, told the ECHO: “Unite has today contacted Essar, who operate the Stanlow oil refinery, to inform the company that due to the ongoing conflict in Ukraine, Unite workers at the facility will under no circumstances unload any Russian oil regardless of the nationality of the vessel which delivers its.
"Essar may believe that it is justifiable to transport Russian oil under a flag of convenience but Unite does not.
"Unite urges the transport secretary Grant Shapps to close this loophole immediately."
A spokesman for Essar said: "Essar remains deeply concerned by the humanitarian crisis unfolding in Ukraine and is fully complying with the statutory framework implemented by the UK government with regard to Russia-related entities.
"Earlier this week, we turned away two cargos of non-Russian origin crude oil which would have been delivered in Russian-flagged tankers.
"We can confirm that a German-flagged vessel was approved to berth at Tranmere Oil Terminal by the Port Authority on Thursday 3 March.
"This vessel set sail for Tranmere on 22 February, before the invasion of Ukraine and the subsequent introduction of UK Government sanctions.
"For a number of days, we have been working urgently to find alternative sources of diesel while simultaneously ensuring uninterrupted supply of fuel to the North West of England.
"Essar will continue to comply fully and will respond promptly to any changes the UK government may make to the statutory framework of sanctions."
The Department for Transport (DfT) announced this week that any Russian owned, chartered or operated ships would be blocked from entering UK ports as part of sweeping sanctions against President Vladimir Putin's regime and its invasion of Ukraine.
Justin Madders, MP for Ellesmere Port and Neston, said: "My understanding is that Essar are lawfully entitled to take this tanker as the current ban relates to Russian ships not their cargo.
"That said, I think everyone who wants to support the people of Ukraine and see the strictest sanctions on Russia possible will agree that the distinction being made between a ban on ships but not their cargo is one that is not morally defensible and urgently needs Government action.
"It is all too easy to see how Russian imports will be able to continue into this country by sailing in under the flags of ships from other countries and I do not believe the public will accept that either.
"I have made my views clear to Essar and have asked them to confirm that they will not take any disciplinary action against employees who refuse to handle this cargo as a matter of conscience.”
Earlier Councillor Jan Williamson, leader of Wirral Council, expressed concern about the vessel's arrival on Twitter, saying "we are looking into this as a matter of urgency."
She later posted: "I have had confirmation that this is a German tanker carrying crude oil, likely for Stanlow.
"This is happening across the country and would require Gov restrictions to put a stop to it."
Other ships carrying liquefied Russian gas arrived in the UK yesterday, but one, the Greek owned Boris Vilkitskiy, was forced to divert from a Thames Valley port after dockers in the Unison trade union refused to unload Russian cargo.
Petrol prices have hit record highs as Putin's murderous war in Ukraine causes havoc with energy markets.
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