The Federal Opposition is in damage control again after Joe Hockey's appearance at the Press Club descended into what even his own colleagues admit was a "shemozzle" yesterday.

Last week Opposition Leader Tony Abbott told the House of Representatives that Mr Hockey would use yesterday's lunchtime speech to give details of the Coalition's proposed budget savings.

But Mr Hockey's speech did not contain any concrete detail on the savings, a task that was left to finance spokesman Andrew Robb, who briefed journalists on the cuts after Mr Hockey made his exit.

The headline figure is $47 billion of savings, but there is devil in the detail. The proposed cuts included axing the Government's computers for schools program as well as green initiatives and the plan to put all Medicare records on a centralised computer database.

The bad day came hard on the heels of Mr Abbott's admission that only his carefully considered, scripted remarks should be taken as gospel truth.

On The 7.30 Report last night Mr Hockey acknowledged that not giving out the Coalition's proposed savings as his leader had promised was not the wisest move.

"With the benefit of hindsight perhaps I should have given [journalists] all the documents half-an-hour earlier," he said.

In his first chance to answer questions on the $47 billion worth of savings, Mr Hockey defended including measures funded by the mining tax, which the Opposition opposes, as a saving.

The Coalition is claiming as a saving any money that it would not spend from revenue it would not get that would have been created by a tax it will not implement.

Mr Hockey also defended the decision to claim as a saving money the Coalition would not borrow to fund a National Broadband Network it would not implement; money the Government says is equity and does not count towards the budget bottom line.

"Borrowings carry. What we announced today was $47 billion of gross savings. That's money we do not have to borrow under the circumstances proposed by the Rudd Government," Mr Hockey said.

Mr Hockey's gross total of $47 billion sounds impressive, but putting the $30 billion from the mining tax and NBN aside at least some of the remaining saving will be spent, with the Coalition saying there will be replacement programs for some of the areas being cut, and in some cases the replacements may cost more.

Mr Robb failed to deliver on a commitment he made to journalists yesterday to release a document by the end of the day outlining all the Coalition's proposed spending to date.

But Mr Hockey says the Opposition still needs more time.

"We will release all of our costings on our own policies as soon as we can get to the bottom of the budget numbers the Government has delivered," Mr Hockey said.

"Quite frankly as at this stage we still haven't got to the bottom of the budget numbers and hopefully we'll get some better information out of the estimates process in the Senate next week."

Reaction from some senior Coalition MPs to Mr Hockey's speech and the savings measures was not good.

One told AM the decision not to release the costings ahead of the speech was "madness", another said the trouble that ensued was not surprising, while others said they were disappointed the savings did not amount to tough decisions.

They say the way they were done stretched conventional budget practice and the Coalition has not yet done the work to win over voters disenchanted with the Government.

Government frontbencher Anthony Albanese told Sky News Mr Hockey's budget reply speech was a shambles.

"Joe Hockey turned up, presented nothing whatsoever and then flick-passed to episode three, Andrew Robb, whose savings don't even add up. It's quite clear that this is not an alternative government," Mr Albanese said.

While the Government has ridiculed the events of yesterday, it still has more than enough troubles of its own. Its mining tax is continuing to cause problems.

Fortescue Metals has officially put two projects on hold. The Prime Minister had to address concerns about the tax at a community cabinet meeting in Tasmania last night, and one of the biggest mining companies, Rio Tinto, will go to the Treasury for consultations on the tax today.

The Government is still struggling to regain momentum after ditching promises, including the emissions trading scheme (ETS).

It has not been the best month for credibility in politics from either side, and the election is creeping ever closer.