A Treasury spokesman said today's Fitch downgrade was a sign that Britain must continue to reduce its debt:
This is a stark reminder that the UK cannot simply run away from its problems, or refuse to deal with a legacy of debt built up over a decade.
Though it is taking time, we are fixing this country's economic problems.
The deficit is down by a third, a million and a quarter new private sector jobs have been created and the credibility we have earned means households and businesses are benefiting from near record-low interest rates.
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".