Members of parliament are due to vote on Tuesday on controversial government plans to place a 1% cap on annual rises in some benefits and tax credits for three years.
The coalition argues benefits should not be rising at a faster rate than inflation, the measure by which they have been historically linked. Benefits increased by more than 5% in 2012-3.
The government wants to to cap increases in jobseeker's allowance, employment and support allowance, income support and elements of housing benefit at 1% until 2016.
Maternity allowance, sick pay, maternity pay and paternity pay as well as the couple and lone parent elements of the working tax credit and the child element of the child tax credit, will also be affected.
The coalition is making the changes - which, if approved, will come into effect in April - as part of its plans to cut the deficit.
But Labour claims they will result in cuts in support for millions of working people.