Those who earn should be better off: PM

Federal Labor is surprised the Abbott government is hinting at changes to the welfare system, with the ink in last week's budget barely dry.

Prime Minister Tony Abbott says people who are working shouldn't be worse off than those on welfare.

The budget papers show that a sole parent earning $30,000 a year with two dependent children under the age of six has a disposable income of more than $66,000 after government assistance, while a single person earning $80,000 with no assistance has a disposable income of just less than $61,000.

Mr Abbott believes any sensible government should ensure the burgeoning welfare system is better organised.

"It is to provide people with a basic level of support but ... you should always be better off in work than out of work," he said.

Treasurer Joe Hockey insists he is not trying to stir up resentment by including such figures in the budget because it is appropriate to spell out how taxpayers' money is distributed.

"We've laid down evidence of where their money is going and I think that is a perfectly reasonable thing to do," he told ABC television.

Shadow treasurer Chris Bowen says if the government has any sensible proposals to make, it should make them, but he believes welfare policy is well targeted.

"The government has just brought down a budget, I would have thought that would entail their policy proposals," Mr Bowen told reporters in Sydney.

Labor has opposed the proposed changes to the commonwealth's paid parental leave scheme and cuts to family tax benefits.

But Mr Hockey says the government has to pay for $3.5 billion of extra childcare support to make the system more affordable.

Yet he is not worried whether the take-up of his new $20,000 instant asset write-off for small business in the budget might be so successful it would blow a hole in the budget.

"It is their own money going back to them over a number of years," he said.

Neither is he buying into speculation of an election earlier than late 2016.

Opposition families spokeswoman Jenny Macklin believes Mr Abbott is preparing for another round of cuts to low income Australians.

"Australians don't want another review. They want a plan for jobs, not just a plan for the prime minister's job," she said in a statement.