Some European Central Bank officials considering whether to retroactively change their generous long-term lending rules for banks reckon doing so is legally feasible, according to people familiar with the matter.

Inflation of 10% and rapidly rising interest rates have eroded the basis for the existing contracts, which were agreed on when price growth was sluggish and borrowing costs were negative, said the officials, who asked not to be identified as the debate is private.

Legal concerns about adjusting the conditions of the so-called TLTROs are surmountable, the people said. Other options being discussed include treating funds created by them similar to minimum reserve requirements, which are remunerated at a lower interest rate, or introducing a system of staggered interest, according to one of them.

ECB President Christine Lagarde said last month that a TLTRO review will be “conducted in due course,” with the Oct. 26-27 meeting the next chance to address the issue. An ECB spokesperson declined to comment.

Without any action, banks that borrowed through the TLTRO program are able to earn a risk-free return on that money by parking it in the ECB’s deposit facility, where rates are currently 0.75% and may be double that by the end of the month.

While officials understand that such a situation is problematic as taxpayers struggle amid soaring energy costs, their main concern is that the credit growth the cheap loans are designed to fuel risks further stoking inflation, which is five times their target.

The ECB has used targeted longer-term refinancing operations since 2014, leaning on them during the pandemic to keep credit flowing to companies and households. The last offering won’t mature until the end of 2024.

Banks are currently charged interest equivalent to the average ECB deposit rate over the life of the loan. Despite borrowing costs now being lifted, that average is held back by eight years in subzero territory.