Homeowners will finally be confronted by rising mortgage payments as the delayed effects of high interest rates kick in, a top European Central Bank official warned.

"There are going to be a lot more people exposed to interest rates,” ECB Chief Economist Philip Lane told an audience in Florence.

Europeans have been largely immune to the crippling effects of the past year's record sequence of interest rate hikes ― the ECB raised its key rate to 4 percent from below zero in just over a year  ― because many had the comfort of fixed-rate deals.

But around 30 percent of those mortgages are due to expire this year.

That will cause them to  “reprice, even though we haven’t raised rates [since the summer], and markets are saying we’re going to cut rates," Lane said.

Higher interest payments means more difficulty for borrowers, and also increase the risk of default — something that could affect banking stability, Lane added.

The degree to which borrowers will be hit varies across Europe. Around 70 percent of loans are due to expire in Spain and Italy, while only around 10 percent will cease in France and Germany.

Around 80 percent of mortgages in the eurozone were fixed as of December, having declined from 2022 in line with demand for loans more broadly.

Many of those fixed-rate loans were arranged when interest rates were low and borrowers were more optimistic, Lane said.