LONDON (Bloomberg) — Britain had its AAA credit rating affirmed by Standard & Poor's, which also kept its negative outlook on the nation's debt on concern the government hasn't been specific enough about how it will cut the budget deficit.

"In the absence of a strong fiscal consolidation plan, the UK's net general government debt burden may approach a level incompatible with a AAA rating," S&P analysts including Trevor Cullinan wrote in a statement published in London yesterday.

"We expect to review the long-term rating and outlook again once medium-term fiscal policy becomes clearer following the 2010 parliamentary elections."

Chancellor of the Exchequer Alistair Darling pledged last week to cut the deficit by about 50 percent to £89 billion ($133 billion) by 2014 from £167 billion this fiscal year. He also said the government would postpone public spending cuts for now, even as unemployment hadn't risen "as much as was feared".

The pound rose against the dollar and was 0.5 percent stronger at $1.4969 as of 4:42 p.m. in London. Government bonds also gained, with the 10-year gilt yield falling five basis points to 3.98 percent. The cost of insuring against losses on British bonds increased, with credit default swaps on five-year debt rising 2.5 basis points to 75.5.

S&P first lowered its outlook on Britain in May and said the nation faced a one in a one in three chance of losing its top rating, which it has held since 1978. Darling said in his budget report on March 24 that he expects the deficit to decline from 11.8 percent of GDP to four percent by April 2015.

The chancellor was scheduled to take part in an hour-long televised debate on the economy with the Conservative Party's George Osborne and Liberal Democrat finance spokesman Vince Cable late yesterday. The Conservatives widened their lead over the ruling Labour Party in two polls published yesterday, though both suggest neither is likely to gain a majority.

A YouGov Plc poll for the Sunday Times newspaper showed the Conservatives ahead by 37 percent to 32 percent. An ICM poll for the News of the World put the Conservatives at 39 percent, compared with Labour's 31 percent.

The rebound in the pound "is likely to be fairly short-lived," said Ian Stannard, currency strategist at BNP Paribas SA in London. "Opinion polls are showing a mixed picture and that's unlikely to provide any lasting support for sterling."