LONDON (AP) — A leading credit ratings agency has warned that Britain faces the prospect of recession if it crashes out of the European Union in March without a deal on future relations.

In a report published Tuesday, Standard & Poor's said "no-deal Brexit could push the U.K. economy into a moderate recession and lower the economy's long-term growth potential."

Most of the loss in economic output the agency projects — about 5.5 percent over three years compared to its base case estimate — would "likely be permanent."

Standard & Poor's also said unemployment could rise to 7.4 percent by 2021 and inflation would more or less double from current rates to 4.7 percent in the middle of 2019.

A "no-deal Brexit," it added, would also lead to a credit rating downgrade.