Using the future fund to invest in infrastructure including a broadband network can be economically responsible and financially viable, said a JP Morgan research report.

The report said that demographic changes such has higher fertility rates and greater work force participation placed less pressure on government finances. The Future Fund has also accumulated more money than anticipated.

Against these trends, money from the Future Fund may be able to pay for infrastructure projects, said the report.

The Future Fund, however, can only fund such projects "if the government has ample cash in its coffers and a little debt and that the opportunity cost of directing all future budget surpluses into the fund is considerable", said the report.

The fund must also be able to pay its public sector pension liabilities by 2009, said the report.

In March, Finance Minister Nick Minchin said that the Future Fund would meet its target by 2009. 

The report said productivity growth has slowed in the last 11 years which in part is due to the lack of investment in new infrastructure.

The Government's Intergenerational Report released in April revised its productivity growth figures downwards from 1.7 per cent to 1.5 per cent.

"This is well below the 2 to 3 per cent range seen in the previous decade," the report said.

"Rebuilding flagging productivity growth via enhancing infrastructure will help alleviate the infrastructure bottlenecks and capacity constraints that are hampering Australia's long-term economic prosperity."

Investing in broadband could also lift productivity especially as Australia ranks 17 of developed countries in the rate of basic internet subscriptions.

In April, Labor flagged it would sell up to $2.7 billion worth of the fund's Telstra shares to finance a national broadband network.