IFS cuts through the confusion

 "In this parliament we will have made £100 billion of savings while cutting income tax by £10.5 billion. In the next parliament we plan to make £25 billion of savings while making £7.2 billion in income tax cuts." - David Cameron, The Times, 30 October

These might be seen as impressive figures—the problem is that they refer to two completely different measurements.

The IFS has helpfully explained the difference. They point out that the £100bn refers to the current government's cuts in relation to what might have been spent if no policies had been implemented since coming to power in 2010. The figure is also projected to the end of 2015/16 and includes changes in payments on the debt interest.

The £25bn of savings refers to the government's planned cuts in real terms spending in 2016/17 and 2017/18—so it only includes two years of the next parliament.  So the government is stating that spending—excluding interest payments on the debts— at the end of 2017/18 will be £25bn less than it was at the start of 2016/17.