The European Banking Authority (EBA) is to publish the results of stress tests carried out on 90 banks across Europe.
The tests act as a financial healthcheck to ensure banks have sufficient capital to deal with difficult economic developments and publicly identify weak banks so national regulators can push them to strengthen their finances.
Regulators also hope the tests will persuade investors that the EU is coming clean about the extent of its banks' problems. Experts believe between five and 15 banks could fall short in today's results, but no large banks are expected to fail.
The EBA has said that the latest tests would be tougher than last year's when only seven out of 91 banks failed. The regulator has analysed some 3,000 pieces of information - as opposed to 149 in 2010 - including how many bonds each bank holds from the financially troubled governments of Greece, Portugal and Ireland.
Banks that fail and those who scrape through will be expected to act on the results and plug capital shortfalls. Some who fail to raise enough capital may have to turn to their own governments.
On Wednesday, German bank Helaba said it expected to pull out of the tests, complaining that the EBA's decision not to accept some of its hybrid capital made the difference between passing and failing.
The Liberal Democrat Sharon Bowles, chairman of the European Parliament's influential Economic and Monetary Policy Committee, accused German banks of covering up results which show they are in urgent need of recapitalisation.
The senior MEP said the results were being manipulated by financial institutions who think "they can fool the market". Germany's "crisis-denial" and its failure to own up to its own difficulties was preventing it from rescuing the European project, she added.
"The banking stress tests will be cathartic for the eurozone sovereign crisis, but not if those seeking secrecy think they can fool the market," Mrs Bowles said. "In their latest round of crisis-denial, German banks are lining up to try and hide what any decent analyst already knows, that there are significant cases of undercapitalisation. Publication of the stress tests will not bring Germany and its banks down, but denial of telling things as they really are lies at the heart of Germany's failure to rescue the euro project."
The latest stress tests come as sources said an emergency meeting of eurozone finance ministers scheduled for today in Brussels to discuss the crisis was abandoned at the last minute after the Germans and the Dutch raised objections.