LONDON, May 21 (Reuters) - Ratings agency Standard & Poor's lowered its outlook on Britain to negative on Thursday while affirming its 'AAA' long-term and 'A-1+' short-term sovereign credit ratings.
"We have revised the outlook on the UK to negative due to our view that, even assuming additional fiscal tightening, the net general government debt burden could approach 100 percent of GDP and remain near that level in the medium term," Standard & Poor's credit analyst David Beers said in a statement.
Beers said S&P had a more cautious view than the UK government of "how quickly the erosion in the government's revenue base may be repaired, the extent to which the growth in government spending can be curtailed, and consequently the pace at which historically high fiscal deficits are likely to narrow".
The June gilt future and the pound tumbled sharply after the announcement.