The Government has been reluctant to provide detail as to how it will assess long-term liabilities against current investment, and has been sitting on a report providing actuarial advice on the issue since October.
Legislation for the second set of reforms will be tabled in Parliament in July, and will streamline benefit categories and clamp down on benefit fraud.
Mr English said the larger work-seeker category will "broaden the base of people that we work with'' and increase the need to focus on getting better outcomes from the system.
"We really want to focus on good results, so services that are nice but aren't that effective need to be changed into services that are very effective,'' he said.
The Government spent some $5.23 billion on benefits and allowances in the seven months ended January 31, some 41 per cent of what it spends on transfers and tax credits, such as superannuation and Working for Families, and 13 per cent of core Crown expenditure.