The Bank of England left its key interest rate unchanged Thursday, mirroring the Federal Reserve while signaling its readiness to raise borrowing costs should high energy prices threaten to cause a broad and persistent pickup in inflation.

The U.K.'s central bank left its key interest rate at 3.75%, where it has been since December.

Prices of oil and natural gas have been highly volatile over recent weeks as hopes for an early reopening of the Strait of Hormuz were dashed by a resumption of hostilities between the U.S. and Iran.

Since the onset of the conflict in late February, policymakers around the world have worried that a prolonged period of high prices for oil and natural gas would prompt businesses to raise their prices as they sought to preserve profit margins, while workers would seek higher wages to maintain their purchasing power.

But the big swings in energy prices makes it difficult for central bankers to be sure that such second-round effects are either inevitable or unlikely. Against that backdrop of uncertainty, the BOE decided to leave its key rate unchanged, while signaling that it is prepared to tighten policy should second-round effects threaten.

"Our job is to make sure any increase in inflation is temporary," said Gov. Andrew Bailey.

As with the Fed vote, there was significant dissent. Three of the nine members of the Monetary Policy Committee voted for a rise in the key interest rate to 4%.

"The key change in my decision is the collapse of the U.S.-Iran Memorandum of Understanding," said Catherine L. Mann, having joined the two MPC members who voted for a rate rise in June. "This sporadic continuance of the conflict appears to be the state of play."