The industrial union IG BCE is urging the federal government to live up to its announced support for maintaining the PCK refinery in the event of an oil embargo against Russia.
"The things that are announced must also happen," said the head of the Berlin-Mark Brandenburg district, Rolf Erler, of the German Press Agency.
As long as this is not the case, there will continue to be fears among the employees.
If they saw that announcements would be implemented, there would be confidence again.
He pointed out that it is not yet clear whether there will be a delivery stop.
Around 1200 people work at PCK.
The EU is discussing an oil embargo against Russia because of the attack on Ukraine.
The PCK refinery is majority owned by the German subsidiary of the Russian state-owned company Rosneft and primarily processes Russian oil from the Druzhba pipeline.
Federal Minister of Economics Robert Habeck (Greens) is looking for new delivery routes for Schwedt via Rostock and Gdansk in Poland.
According to estimates, this would only achieve 60 to 70 percent of the refinery's previous output.
At the same time, Habeck relies on financial aid for possible additional costs after the changeover and on the option of a trust structure instead of the operator Rosneft Germany.
During a visit to Schwedt, the Economics Minister said that it was always about preserving the location as fully as possible.
In the long term, the refinery is concerned with a possible transition to hydrogen.
The IG BCE will follow the further steps of the federal government closely, announced district manager Erler.
The Brandenburg state government also supports preservation.
Prime Minister Dietmar Woidke (SPD) had warned that an embargo would jeopardize security of supply in parts of eastern Germany.
According to the PCK, 90 percent of the cars in Berlin and Brandenburg run on fuel from Schwedt.
The Berlin-Brandenburg business association and the Uckermark business association are calling for the rejection of an oil embargo.