Chancellor George Osborne is under pressure to change economic policy
UK borrowing is likely to be £64bn higher in 2014-15 than forecast, according to a closely watched report.
The Institute for Fiscal Studies (IFS) says that a weaker-than-expected economy will mean the government has to borrow a lot more, unless it imposes tax rises and further spending cuts.
Public service spending could fall by a third by 2018, the IFS said.
The cuts could lead to the loss of about 1.2 million public sector jobs, it said in its Green Budget 2013.