A reinvigorated Joe Hockey has again implored businesses and consumers to flash their credit cards in a bid to jump-start stubbornly flatlining consumer and business confidence, arguing his everyone-is-a-winner budget has set the conditions for optimism and growth.

"This is a great opportunity for Australia to be more prosperous," he said, dismissing suggestions the budget had been designed to fight an early election even as Prime Minister Tony Abbott declined to completely rule the option out.

But the newly ebullient Treasurer has conceded one of his budget's key stimulus measures, the accelerated depreciation tax deduction for small business, has had to be funded out of general revenue despite earlier stipulating that all new spending would be offset by new and equivalent savings.

And as the details of the budget become clearer, the government has also found itself on the back foot over tightened eligibility for paid parental leave.

The admission that the 100 per cent instant asset write-off for small business paid for by borrowings – given the deficit currently sits at $41.1 billion - came as Mr Hockey used his post-budget address to the National Press Club to hammer the theme of confidence, defending an increased tax-to-GDP ratio which will climb to a seven-year high of 24 per cent in 2015-16 while imploring Australians to get out and spend.

Asked what offsets had been initiated to fund the business tax break, Mr Hockey said: "It's based on good policy and the fact that we have improved the budget bottom line."

"We're not tying it to any particular initiative," he said.

Myers and JB Hi-Fi shares closed higher on Wednesday after the government announced it would scrap fringe benefits tax on portable digital devices such as mobile phones, iPad and similar tablets and laptop computers.

The switch to stimulus mode has been broadly welcomed, especially within the stressed and, until now, dejected ranks of the Coalition party room, where the last budget had done so much to sap morale and dampen re-election hopes.

Fairfax Media has been told Liberal MPs have received numerous calls and emails in their electorate offices from small business owners and others seeking clarification on when they can start buying new equipment with each purchase attracting a maximum $20,000 immediate deduction.

Warming to his new mode of spruiker-in-chief for a spending-led recovery, Mr Hockey said the aim of the budget had been to manage "head winds" and would now move to capitalise on a raft of increasingly favourable economic conditions.

He said the conditions would see the economy grow steadily towards an annual growth figure of 3.5 per cent within three years from its sluggish 2.75 per cent in the coming year.

"We have to deal with the head winds that we face, but our plan is carefully thought-through, it is working," he said.

"Australia is getting better, the economy is getting stronger, the budget is going to be better, there are going to be more jobs, there's going to be more exports, greater prosperity, asset values are going up, it is a positive story and now, as I've said last night, is a time for Australians to have a go," he said.

"To have a go, as the PM said, for a fair go, have a go."

While the government has a spring in its step,  it faces new pressure over its crackdown on the so-called "double-dipping" by new mothers who get both employer-funded parental leave and the government-funded scheme.

The opposition homed in on the words of Mr Hockey in a pre-budget interview with Nine's Laurie Oakes on Sunday when he explicitly agreed that such a practice constituted "fraud".

Whether by design or oversight, the government's move against paid parental leave "double-dippers" has emerged as the flashpoint in the budget's immediate aftermath. It is likely to feature strongly in Bill Shorten's official address-in-reply speech on Thursday evening.

But as the government showed a sensitivity to voter anxiety absent from its first budget, Mr Hockey ruled out a review of Australia's retirement incomes system, a review he had previously said was under "active consideration".

Asked at the National Press Club whether there would be any point in a review after he declared in the budget there would be "no new taxes on superannuation under this government", he said he and his colleagues had had their "fill of reviews".

"Changing the taxation regime for superannuation is certainly not the answer," he said. "Having a review at this point of time is not the answer either. We have no plans to have it reviewed."

With Peter Martin

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