The Government was spending and borrowing more than it could afford into the future. So it made sense to reorganise the Government's assets and redeploy capital to priority areas without having to borrow more.
"Most nights on television, we see the consequences of countries in Europe and elsewhere borrowing too much. We don't want that for New Zealand."
Prime Minister John Key will spell out the Government's thinking on public sector reform in a speech next month but more job cuts and mergers of agencies are a given.
Restructuring of the once untouchable Ministry of Foreign Affairs and Trade will be outlined today.
Mr English said that the Government's commitment to absorb the shock of the global financial crisis on its own balance sheet could not continue.
"We told public sector chief executives to look at their own operations and tell us how they could be improved to deliver better services with little or no new money.
"We gave them time to do that. We're now at that point."
The changes ahead would help general productivity in the economy.
The public sector made up about a quarter of the real economy ''and it has been a drag on overall productivity."
Referring to social welfare reform which will apply tougher work tests on sole parents and address youth employment, Mr English said the Government would move quickly to get reforms underway.
He said it was staggering that around one in eight New Zealanders aged 18 to 64 was on a benefit and about half of them had spent at five of the past 10 years on a benefit.
"That's not only bad for the beneficiaries and their children, it's a waste for society and taxpayers."