MADRID — Spain appears poised to seek a bailout of its ailing banks, a long-anticipated acknowledgment by the government of Prime Minister Mariano Rajoy of the depths of Spain’s economic crisis.


The only questions might be when, and how much.


By some estimates, Spain’s banks might need as much as 100 billion euros ($125 billion). European leaders are said to prefer throwing a lifeline to Spanish banks now, though, rather than waiting for the banking problems to swamp Spain’s entire economy, which might require a full-scale bailout of the Spanish government that Europe can ill afford.


But the bailout cannot begin until Spain formally requests it. And while some European leaders press Madrid to get on with the process, the Spanish government says it wants a fuller accounting of how much money it actually needs. Officials from around the euro zone on Friday were deflecting news reports that finance ministers would be conferring over the weekend to draw up a rescue package.


On Friday, Spain’s deputy prime minister, Soraya Sáenz de Santamaría, suggested that her country would make no bailout request at least until after a banking audit expected Monday from the International Monetary Fund, as well as audits due June 21 from two independent consulting firms.


Madrid evidently wants to avoid a miscalculation after significantly underestimating the problems at Bankia, a giant mortgage lender that was nationalized a month ago because of the mounting number of bad loans on its books.


But there is increasing pressure from German and other European officials to force Spain to accept a banking bailout deal before June 17. That is the date of Greek parliamentary elections that could prompt Greece to seek an exit from the euro union, potentially beginning a disintegration of the common currency.


Officials from other euro zone economies are trying frantically to increase pressure on Madrid to seek outside help “pre-emptively,” without waiting for those banking audit results, to remove one significant area of stress and uncertainty from the markets in case the Greek election “goes sideways,” according to two people close to the talks who were not authorized to speak publicly.


“This doesn’t mean at all that you get agreement on all the details” right away, one of the people said. But it would allow euro finance ministers to “get a framework around the Spanish situation” and “free up human capital” to deal with any fallout from the Greek election, this person said. “It’s really designed to manage the Greece situation and try to tie up as many loose ends as possible.”


Germany’s chancellor, Angela Merkel, in a news conference on Friday, denied that Germany was applying pressure on Spain but said that help would be there if needed.


“We have everything that is necessary for a stable development of the euro zone,” Ms. Merkel said, “and now it is, so to speak, up to the individual countries to turn to us. That has not happened yet. Therefore, Germany also won’t exert in any way any pressure here.”


This week, the French finance minister, Pierre Moscovici, said Europe was ready to help Spain if needed.


Until a few days ago, Mr. Rajoy had been delaying making the request in part because he reportedly hoped that the European Central Bank would step in, or that he could persuade other euro zone governments to agree to lend the money directly to the banks, to avoid adding to the Madrid government’s own debt load.


But Mario Draghi, the president of the central bank, made clear during the last week that he was not going to intervene. And European officials have stressed that any bailout would have to go through the Madrid government, even if Europe imposed few conditions on Spain in return for such assistance.


Since the start of the euro debt crisis more than two years ago, three governments — in Greece, Ireland and Portugal — have had to request bailouts. And those came with stringent budget and spending conditions imposed by the European Commission, the central bank and the International Monetary Fund. It is those conditions that have caused a political upheaval in Greece, where the Coalition of the Radical Left party, or Syriza, led by Alexis Tsipras, has vowed that if it comes to power it will refuse to live up to the nation’s bailout terms.