The main risks to the South African economy remain external, Finance Minister Pravin Gordhan said on Friday.

Speaking in the National Assembly during debate on his budget vote, Gordhan said global economic growth had remained weak this year, as was anticipated at the time of the Budget in February.

"Growth in output in our own economy is uneven and slow, though consumption spending is still buoyant," he said.

"But the challenge we face is not just growth, it is a more broad-based transformation; not just development, but structural change that will extend opportunities to the unemployed, and unshackle the enterprise potential of our people."

The domestic economy was showing some signs of moderate growth but the external environment remained weak and risks were high.

The most recent data from the South African Reserve Bank, for the last quarter of 2011, showed that household consumption and investment were still growing robustly.

Consumption grew by 4.6 percent in the quarter, investment by 7.2 percent, and government consumption grew by 7.3 percent.

National Treasury forecast that household consumption and investment would continue to grow robustly in 2012, and government spending would also support growth.

However, output growth in the first quarter of this year was slower than forecast, mainly due to the effect of the Impala Platinum strike on mining production.

Retail sales had also slowed somewhat. Mining output recovered in March, growing by 5.3 percent month-on-month, but manufacturing production was disappointing, falling by 4.3 percent.

"Monthly figures are volatile, but it is clear that investment is still held back by both global and domestic uncertainties," he said.

Leading indicators, such as the Kagiso Purchasing Managers Index and the Reserve Bank's Composite Leading Business Cycle Indicator, pointed to continued growth but at a moderate rate.

Despite high oil prices and a weaker exchange rate, inflationary pressures had remained relatively subdued.

"The main risks to the economy remain external. Political developments in the Eurozone have heightened the risk that Greece will exit the single currency within the next year, though there is little clarity on how this would be achieved and what its impacts would be."

More serious for both the global economy and the potential impact on South Africa was the continuing vulnerability of several larger European economies, including Spain.

A large budget deficit and a deflating housing bubble had reduced confidence in government finances and the solvency of Spanish banks.

"Our expectation is still that there will be a shallow recession in the Eurozone, but the risk of a deeper contraction has grown since the Budget."

The US should post subdued but positive growth in 2012, at a pace similar to the 2.2 percent expansion in the first quarter of this year.

The US recovery was not as robust as expected, and it appeared likely that fiscal contraction would subtract from US growth in 2013.

Gordhan said there were also risks to Chinese growth, due to slowing exports to the Eurozone area and a deflating domestic housing bubble.

Easier monetary policy should help sustain China's growth, but it was expected to slow, he said.