Governments and parliamentarians also disagree on how quickly to build up the shared resolution fund and how soon all the money in it should be accessible to all countries.
The fund will be filled from contributions of all euro zone banks and is to reach, eventually, around 55 billion euros ($76 billion).
Governments want the fund to reach full capacity over 10 years and agreed the amount of money that would be available to all euro zone countries would increase by 10 percent each year, so that the fund would be fully mutualised after a decade.
In the meantime, if a euro zone country does not have enough money accumulated from the contributions of its own banks to cover the costs of closing one, its government would have to come up with the cash. If it cannot borrow that from the markets, it could ask the euro zone bailout fund for a loan.
The parliament believes this would not break the vicious circle of highly indebted governments trying to rescue banks that are failing because they lent to the government.
(Read more: 'Doom loop' for Europe's debt markets)
Parliamentarians therefore want all bank contributions to the resolutionfund to be fully available to all euro zone countries after three years, not 10.
This could make it unnecessary for governments to borrow at all, providing relief to battered public finances.
Whether banks would therefore have to pay in all the 55 billion more quickly as a result is another contentious issue.
Finally, policymakers have to decide if they will allow the single resolution fund to borrow on the market against the security of future contributions from banks if it is short of cash at any point, or if it should be allowed to borrow from the euro zone bailout fund or given government guarantees.
Even though all these issues have been known since early December, there has been no progress so far.
"No major issue has been solved, because we will go for solving them all together," the EU official said.
A deal is to be worked out over Monday and Tuesday, when euro zone and EU finance ministers meet to amend their initial position from December, and Wednesday when they will present the new stance to parliament.
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