LONDON, May 21 (UPI) -- Credit rating company Standard & Poor's held Britain's rating to triple A, but issued a threat to its standing, which shook London's stock markets Thursday.
S&P said its assessment of Britain's credit was "negative," as opposed to its previous assessment of "stable," The Times of London reported.
On official report said the British Treasury borrowed $13.29 billion in April, a record for the month. A year ago, the Treasury borrowed $2.8 billion to get through the month, the Times said.
Britain's debt reaching $13.2 billion also rattled the London market, which dropped 122.94 points to 4,345.47, off 2.75 percent.
In Chancellor of the Exchequer Alistair Darling's April's budget, borrowing for the government's next fiscal year was headed for $273 billion, about 12.4 percent of the national income, the Times said.
"A government debt burden of that level, if sustained, would in Standard & Poor's view be incompatible with a 'AAA' rating," S&P said.