“I believe that this generation could see a revolution in our social economy comparable to the revolution in the commercial economy in the 1980s. That is the revolution that I want to lead (…). Don’t we need the same transformation in the social sphere that we have seen in the economic sphere? “.

These words, spoken by David Cameron in a speech in 2006, were and are highly laudable. However judged by the harsh realpolitik benchmark of what he achieved at the G8 Summit with his initiative on social investment, action has not matched rhetoric. Yes, Mr Cameron announced a number of domestic initiatives, all of which are to be praised. But where was the radical ambition of 2006? He could, for example, have taken steps to get the foundation sector to align their core endowment funds with their social mission. Or, since this was G8, why did he not announce an extension and development of his government’s modest commitment of $50 million for the CDC impact fund to fight against global poverty?

Mr Cameron’s 2006 vision remains valid. At the end of the day, social entrepreneurship and impact investing are simply the injection of modern capital and commercial practices into the provision of social goods. In financial and strategic terms, the opportunity and paradox is that in the traditional “for” profit world we are reaping the whirlwind of over-leverage, whilst in the “not for profit” world there is under-leverage. Yet if the social sector can leverage capital effectively through new financial products, the incentives for collaboration and scale will change fundamentally.

The social finance revolution, and the political flag of the Big Society that it sailed under, has been cynically seen as an attempt to save a bit of cash and reduce the public deficit. It should be an issue that is bipartisan: it moves resource to issues the Left care about and, to the Right, it is about driving modern commercial practices and efficiency into a sector they have always regarded with some suspicion. But what both the Big Society policy and the G8 Summit on impact investing lack is a statement of why it is so necessary  - TINA (‘There Is No Alternative’) in Conservative language.

To give you an idea of the potential of impact investing as a critical strategic building block of our societies, if by 2020 just 20% of US foundation assets were allocated to mission-related investment – that is a less than 2% annual change in core asset allocation for Foundations between now and 2020 – this would make $125bn available for solving social problems. Even better, these assets could be leveraged a further three times to bring in other investors – a sum equivalent to current total core funds of the foundation sector.  And that’s just in the US. Or, to take another example, according to the World Bank there are nearly $2 trillion in local capital pension fund markets in developing countries that could be harnessed much more effectively to help those countries’ sustainable development.

And it is not just about the money. There is a plethora of “new” financial tools that can be applied to this market in real scale. The Prime Minister repeatedly mentioned Social Impact Bonds - an innovation I was involved in from birth – but there is much more that could be done with this type of product to strengthen the incentives to collaboration, scale and rapid achievement of social objective. The big issue is not the funding of Newcastle Swimming Pools or individual social entrepreneurs, it is changing the fundamental flows of capital.

What is only too clear to protagonists is that the supporting infrastructure to drive this revolution in financing the social sector is unaligned and unfocused. It is here Government must play a clearer structural role. It is about moving from being an element of Finance Policy to an integrated Policy Finance approach. To drive real change requires a clear understanding from Government as to the nature, ecosystem and regulation of this developing trilateral relationship between the corporate sector, civil society and government. Let us hope that for impact investing, as Mr Cameron’s most-celebrated predecessor Winston Churchill said, “it is not the end, it is not beginning of the end, but perhaps it is the end of the beginning”.