Fitch Ratings has downgraded the UK from AAA to AA+, but said that the outlook is stable.
The rating actions follow the conclusion of the review of the UK's sovereign ratings initiated on 22 March.
Fitch has explained that the reason for the downgrade is that despite the UK's "strong fiscal financing flexibility", its ability to absorb further adverse economic shocks is "no longer consistent with an 'AAA' rating".
More top news
The victims of the Shoreham air crash will be remembered in a series of events today to mark one week since at least 11 people were killed.
Jose Mourinho's treatment of Chelsea team doctor Eva Carneiro is to be discussed by a FIFA committee, it has emerged.
Elsewhere it’s largely dry, sunny and increasingly humid across the bulk of England and Wales.