Woolworths has told some suppliers it could decide to pull their products from shelves just days before Christmas if they refuse to cut prices and fund the supermarket giant's new Cheap Cheap advertising campaign.

Just 62 individuals own the same amount as half the world's population - and the system is ''rigged'' in their favour.

National Australia Bank on Tuesday became the second of Australia's big four banks to change its call on interest rates next year after its closely-watched business survey revealed gloomy findings supporting rate cuts in 2015.

Falling oil and iron ore prices, coupled with a faltering China, are likely to further test investor nerves amid expectations that all three will emerge in this week’s mid-year budget update as Australia’s Achilles heel.

The government's budget deficit will hit a staggering $40.4 billion this year, Treasurer Joe Hockey says, with the budget to return to surplus one year later than expected.