The ECB is apparently prepared to provide a financial back-up solution for Ukrainian refugees in return for EU guarantees.
This emerges from an ECB paper seen by Reuters, which the European Central Bank sent to the EU Commission last week.
The aim is to create a mechanism that will enable millions of Ukrainian refugees in the EU to exchange their hryvnia, which is practically worthless abroad, for euros.
The ECB proposes in the paper that it and the national central banks act effectively as financial trustees for the EU.
The governments of the EU states would only give the central banks the order to set up the exchange mechanism and at the same time provide the money for it.
According to an EU insider, there is strong support among member states to provide the ECB with an EU-wide guarantee for such a swap operation.
The German banking industry is also opting for a European approach when it comes to exchanging refugees' Ukrainian currency for euros.
From the ECB's point of view, an alternative option would be if the central bank of Ukraine gave it a corresponding mandate for an exchange campaign.
Formally, the ECB could then conclude a contract in which it would act as its trustee.
The EU could therefore build in a financial safeguard via its budget, according to which it would assume the costs should the Ukrainian central bank fail to meet the financial obligations of the treaty in times of war.
The agreement could then set an exchange rate, a cap on amounts to be paid out, and the duration of the agreement.
An exchange mechanism for stranded Ukrainians is also possible for countries outside the euro zone.
At 2.3 million, the majority of war refugees from Ukraine have fled to Poland, which is not part of the euro zone.
There are also many Ukrainians in the EU states of Romania, Slovakia and Hungary.
Only Slovakia is a member of the euro zone in this region.
In times of war in Ukraine, the ECB is already supplying countries outside the monetary union with new or extended liquidity lines.