The budget deficit remains the key issue facing Finance Minister Pravin Gordhan when he makes his first budget speech in Cape Town on Wednesday.

Consultancy KPMG said in a statement on Tuesday that the minister had to address the difference between tax revenue and expenditure in a responsible manner.

"From a relatively small proportion of tax contributors that have been efficiently tapped into by the South African Revenue Service (Sars), more needs to be derived.

"This excludes the shrinking corporate and Value-Added Tax base - both facing increasing constraints because of consumer caution in spending and depressed demand."

KPMG said the usual 'sin taxes' were likely to go up, but the stable tax base comprising company tax, VAT and personal taxes seemed to have represented finite resources in the face of Sars efficiencies.

"Taxation, then - the past stomping-ground of increasing-efficiencies of the new minister - represents an area of narrow scope for continued growing state income generation through hyper-efficiencies."

Infrastructure investment had long been a government priority, but was dependent on the health of the fiscus at national, provincial and local levels.

"While there are arguments for soft and hard infrastructure priorities, the National Health Insurance (NHI) system should emerge as a priority," KPMG said.

"Although the devil languishes in the detail of the allocation of funding and the mechanics of roll-out, there have been a number of clear indications that this remains a government priority."

The NHI formed part of government's intent to address the inequalities of society and a certain allocation should be made to it - even if it was only for the purpose of researching the administration and implementation of the scheme, KPMG said.

"While it was not an issue explicitly addressed in the State of the Nation speech, the financial implications of the idea might compel the finance minister to address it."

There were also a number of indications that the Minister of Finance would address issues affecting the environment.

"Apart from the targets announced by President [Jacob] Zuma at Copenhagen, in December 2009, that targets have been set for the reduction of carbon emissions, announcements have come from government affecting the automobile sector and indicate a seriousness of intent to address this matter," KPMG said.

This was well in advance of South Africa's Copenhagen commitments, it added.

"It is likely that the Minister of Finance will not await the White Paper expected to be released during the middle of this year to address the matter in greater detail."

KPMG said that while the FIFA World Cup might bring short-term spending, it is the long-term benefits that needed to be appreciated.

"Developing infrastructure, beyond stadia, transport, policing and other long-term investment has been the goal of the 2010 football effort.

"While all of the latter are of great significance, addressing the post-2010 infrastructure environment, physical and economic, will be a key challenge faced in the 2010 budget vote delivered by Gordhan."