LONDON — The Bank of England raised interest rates on Thursday to their highest levels in nearly a decade as it seeks to tamp down inflation and make preparations for a potential economic downturn as Britain exits the European Union.

Policymakers at the central bank voted unanimously to raise the benchmark interest rate a quarter of a percentage point on Thursday, to 0.75 percent, the highest it has been since February 2009.

Before the decision, they voiced concern about inflation, which, at 2.4 percent, is above the bank’s 2 percent target. And while wage growth appears to be relatively weak, the bank nevertheless anticipates an acceleration in price rises because the lowest levels of unemployment since 1975 will probably force employers to pay more to retain staff. A public sector raise announced at the end of July could also bolster wages and, by extension, inflation.

In its quarterly inflation report, which accompanied the rate-setting meeting, the Bank of England said inflation was most likely to fall slowly to about 2.1 percent in a couple of years.