John Key's defending his zero Budget, while Labour leader David Shearer is expected to attack the Government's policies and economic performance in a speech later today.
The Greens have also released independent research critical of the Government's partial asset sales policy to kick off Budget week.
The Prime Minister says if the Government spends more than it has, then the country will end up like Greece.
"I noticed this morning David Shearer saying well zero Budget means zero growth. Well that may be what the Labour Party think that the only way to grow an economy is to spend money you don't have via taxpayers but in fact, the way to grow an economy of course, is with an vibrant economy."
Mr Key says that involves a private sector which can get things done.
Meanwhile fresh attacks are about to be made by the Green Party on the Government's economic agenda and its partial assets sales program.
Co-leader Russel Norman's called a news conference for later today where he'll release new research he and his party claims shows the policy is a mistake.
"We wanted to commission some independent research from BERL (Business and Economic Research Limited) looking at what will be the Budget or fiscal implications of asset sales because we're pretty concerned that actually it will be very, very negative for the Government's position."
Mr Norman's giving little away about the findings other than to say they'll show the Government's plans will leave its finances worse off over the longer term.
And the Green Party wants the company tax rate reconsidered
Mr Norman says the Government's original argument in setting the tax rate at 28 cents was that we had to match Australia.
"Australia hasn't gone there, they've stayed at 30 and also Inland Revenue made it very clear that the reduction in the company tax rate wasn't attracting overseas investment so it's hard to see what the justification remains for putting it down to 28 cents."
Mr Norman says his party's policy would be to put the company tax rate up to 30 cents in the dollar, while the post-quake rebuild in Christchurch is carried out.
In addition, another hike in the price of tobacco could be on the cards when the Government delivers its Budget on Thursday.
A three phase increase in the price of tobacco was introduced in the 2010 Budget with this year being the last stage of a series of 10 percent price increases on cigarettes.
The Government's coy on specific details, but so far hasn't denied there's more to come.
There's speculation it intends further increasing excise rates on cigarettes and loose tobacco.
Photo: John Key (Getty Images)