LONDON –  Credit ratings agency Moody's Investors Service has downgraded Britain's government bond rating one notch from the top AAA to AA1, citing weaknesses in the economy's medium-term outlook.

Moody's said Friday that "subdued" growth prospects and a "high and rising debt burden" were weighing on the British economy.

The British government is in the midst of a program of spending cuts designed to reduce the nation's hefty deficit, but a flat-lining economy has led it to downgrade its own estimates of future growth.