Former prime minister Kevin Rudd has attacked the Coalition's broadband internet policy, declaring that many parts of Australia will become "economic backwaters" under Tony Abbott's plan.

Mr Rudd has used a wide-ranging speech to the Urban Development Institute in Melbourne to defend Labor's legacy of infrastructure investment and education spending, arguing it will help Australia take advantage of new opportunities in Asia.

He says the economic benefits of the multi-billion dollar National Broadband Network (NBN) will be "mind blowing", but would be put at risk by a future Coalition government.

"Over 12 years in office, there was something like 12 Coalition plans to roll out broadband across Australia. They all failed," Mr Rudd told the audience.

"And Mr Abbott's plan for the future appears to be the same again.

"This will render our major cities and our regional centres absolute economic backwaters compared to the rest of the world, which is heading in exactly the reverse direction."

Under the Coalition's broadband plan, fibre optic cable would be connected to neighbourhood 'nodes' instead of individual homes, which it claims would reduce the rollout time and cut back the cost.

Opposition communications spokesman Malcolm Turnbull says his policy would prioritise areas of greatest need first and be upgraded later.

"Our plan is to ensure all Australians get access to very fast broadband and that is delivered sooner than Labor would be able to deliver with their approach, cheaper in the sense of less cost to the taxpayer, and more affordably for consumers," Mr Turnbull told ABC Radio National.

"We'll use a mix of technologies... including fibre to the node. So you'll have some fibre to the node, some fibre to the premises, some wireless, some satellite.

"Taking that approach, we'll be acting consistently with what is being done in North America, in Germany, in the United Kingdom and indeed in most countries."

Mr Turnbull says he cannot yet quantify the cost of his plan, because it is not clear how "locked in" the National Broadband Network company is with its many contracts.

'Stronger and richer'

Broadband internet policy has been a key point of difference between the major parties since Mr Rudd first proposed the NBN as Labor leader.

Mr Rudd used his speech to also highlight the benefits of a growing population, pointing to the successive generations of migrants that have made Australia "stronger and richer" than it otherwise would have been.

He said that if Australia had "shut the door" to immigration after World War II, the country's population would now be only about eight million people.

"Instead we have managed to become the 12th-largest economy in the world, a member of the G20, whose summit we will host in Australia next year, by far the most significant international gathering of heads of government ever held in our nation's history," he said.

But he says Australia is facing a long-term fiscal challenge because the average age of the population is growing and requiring more expensive medical care, while at the same time the proportion of people in the workforce is diminishing.

"Government policy must therefore aim to encourage more people into the workforce, to re-enter the workforce, and to remain there for longer if that is their wish," he said.

Mr Rudd says the growing population and trend towards city living is also putting a strain on the nation's infrastructure, but argues that public transport spending since 2007 under Labor has been higher than all federal governments combined since 1901.

He has backed Julia Gillard's decision to base herself in western Sydney for the week, saying: "It is entirely appropriate that the Prime Minister and the Cabinet spends time this week examining the infrastructure needs of our biggest city".