Chancellor George Osborne has announced a fresh squeeze on benefits, as he admits the UK economy is performing less well than expected.
Austerity measures will be extended to 2018 and Mr Osborne looks set to miss key debt-reduction targets.
He also announced more money for roads and schools and axed a planned 3p fuel duty rise, in his Autumn Statement.
He said "turning back now would be a disaster" for the UK. But Labour said his credibility was "in tatters".
Mr Osborne had said debt would start falling as a proportion of GDP by 2015/16 - the year of the next general election.
But he has been forced to delay that target by a year because of the worse than expected state of the economy, which is now expected to shrink this year by 0.1%.
The Office for Budgetary Responsibility says the UK has a "better than 50% chance of eliminating the structural current deficit in five years time", said the chancellor - meaning his other key objective has been pushed back by a year to 2017/18.
'In this together'This move heralds a fresh benefits squeeze and a raid on the pensions of the wealthy.
Most working age benefits, such as Jobseekers Allowance and Child Benefit, will go up by 1%, less than the rate of inflation, for the next three years.
MPs are due to vote on the benefit squeeze, although Labour has yet to decide whether it will oppose the move.
"We need to see the detail," said the shadow chief secretary to the Treasury, Rachel Reeves.
"I just don't think it can be right to be cutting the support for those people on modest incomes and those people who through no fault of their own have lost their jobs"
And there will be a further cut in tax relief on large pension pots, saving £1bn a year - something the chancellor said proved "we are all in it together".
In other moves: Teachers pay in England and Wales will be more closely linked to performance
The go-ahead is given for 30 new gas-fired power stations
An extra £1bn will be spent on road building projects, including the conversion of the remaining A1 dual carriageway from Leeds to Newcastle into a motorway
Plans to reduce council budgets in England are branded "unsustainable" by the Local Government Association
A consultation is launched on easing the burden on companies of running final-salary pension schemes
The private finance initiative (PFI) is to be made more public and less private
The Lib Dems mistakenly issued a press release attacking Tory tax policies
Income tax personal allowances will go up by £1,335 - £235 more than previously announced - so no tax will be paid on earnings under £9,440.
The threshold for the 40% rate of income tax is to rise by 1% in 2014 and 2015 from £41,450 to £41,865 and then £42,285.
The basic state pension will rise by 2.5% next year to £110.15 a week.