Deputy Director of the Institute for Fiscal Studies (IFS) Carl Emmerson said that since the last Budget, the UK's economic outlook has "deteriorated" and Government receipts have "disappointed".
Mr Emmerson suggests that as a result, Chancellor George Osborne might find himself having to "abandon" one of his fiscal targets.
If much of the additional weakness this year feeds into a permanently higher outlook for borrowing, then in order to comply with his other fiscal target Mr Osborne would need to announce yet more tax rises or spending cuts for the next parliament in next week's Autumn Statement.
In that case the planned era of austerity could run for eight years - from 2010/11 to 2017/18.
More top news
The first lady visited Upbring New Hope Children’s Centre.
Sir Philip’s firm Taveta Investments is seeking an injunction to restrict publication of a report by the accountancy watchdog on a BHS audit
The US president took executive action aimed at curbing the separation of families.