Standard & Poor’s announced Monday that it has lowered the United Kingdom’s sovereign credit rating from “AAA” to “AA.” S&P cited last week’s U.K. referendum to leave the European Union in its explanation of the rating decline.

“In our opinion, this outcome is a seminal event, and will lead to a less predictable, stable, and effective policy framework in the U.K. We have reassessed our view of the U.K.’s institutional assessment and now no longer consider it a strength in our assessment of the rating,” the ratings agency said in a news release. READ MORE