Britain's budget deficit widened to the biggest on record for any August, data showed on Friday, a day after the central bank governor said overshooting budget targets may now be acceptable.
The government said a weak economy pushed down corporation tax receipts and drove up benefit payments.
As a result, public sector net borrowing excluding financial sector interventions - the government's preferred measure - rose last month to 14.410 billion pounds from 14.365 billion in August 2011.
That was the highest for any August since records began in January 1993, although slightly below economists' forecast in a Reuters poll for 15.0 billion pounds.
Chancellor George Osborne, who has made reducing the deficit a central plank of his policies, may soon face a tough choice between imposing more spending cuts or abandoning his goal of ensuring that the debt-to-GDP ratio starts falling by 2015.
Late on Thursday, Bank of England Governor Mervyn King - a firm supporter of the government's efforts to cut the budget gap - said missing the reduction goal would be acceptable if the reason was weakness in the global economy.
In March, the state forecasting body - the Office for Budget Responsibility - predicted public sector net borrowing would amount to 5.8 percent of GDP in the 2012/13 fiscal year. Economists said that target now looked unattainable.
By way of contrast, countries in the euro zone - deemed to be in a debt crisis that Britain has largely escaped if its record low borrowing costs are any guide - are striving to shrink their budget deficits to 3 percent of GDP over the next year.
"The (UK) overshoot is a result of reduced corporate tax receipts and increased government benefit costs," RBS economist Ross Walker said. "In an absolute sense they're bad numbers, but they're consistent with the overall trend."
David Tinsley, an economist at BNP Paribas, said the government now risked missing its targets by as much as 20 billion pounds.
In his annual Autumn Statement on December 5, Osborne is likely to face a downgrade in the OBR's growth forecast, as well as a gloomier prediction for the budget deficit.
He is already under pressure to loosen his austerity drive as Britain's economy is struggling to move out of recession and a meaningful recovery looks elusive.
Bank policymaker Spencer Dale said earlier on Friday the economic backdrop was still "pretty challenging", but that there were encouraging signs from local businesses that access to bank finance was becoming easier due to the BoE's new Funding for Lending Scheme.
Borrowing in the fiscal year to date actually fell to 31.003 billion pounds from 48.446 billion in the April-August period 2011.
However, stripping out the transfer of Royal Mail pension assets, the deficit stood at 59.0 billion pounds, up 21.8 percent compared with April-August 2011 -- far above the OBR's forecast for the full year of an increase by just 0.5 percent.
The government had originally planned to eliminate the structural budget deficit by 2015 with a tough programme of spending cuts and tax rises.
But a weak economy has forced it to extend austerity by another two years and Prime Minister David Cameron has warned austerity could last even longer -- until 2020.
Friday's data showed that government receipts rose 1.8 percent on the year in August, while current spending grew 2.5 percent. Within that, corporation tax inflows fell 2.1 percent on the year, while social benefit payments rose 4.9 percent. (Additional reporting by David Milliken. Editing by Jeremy Gaunt.)