European Central Bank Vice President Luis de Guindos said inflation is sure to moderate but the pullback in core price pressures may not be so pronounced.

“There is not doubt inflation will ease,” Guindos said Monday in Madrid. “Underlying prices, however, could face more limitations in the that slowdown.”

Core inflation has emerged as the key measure of inflation for ECB policymakers, who’re in the midst of an unprecedented monetary-tightening cycle to get price gains back to the 2% target. How the gauge develops will likely determine whether rate hikes persist into the fall.