The ruling party would not use its majority to alter the two-term limitation on serving presidents, or make any other fundamental constitutional changes, President Thabo Mbeki said on Sunday.
In an interview with the South African Broadcasting Corporation, he denied having aspirations of standing for a third term as the country's leader.
"By the end of 2009, I will have been in a senior position in government for 15 years. I think that's too long," he said.
"I think that after 15 years, I should step aside in any case."
Formerly deputy president, Mbeki succeeded Nelson Mandela as leader in 1999, and entered a second five-year term following the elections in 2004.
The South African National Civics Organisation has called for a debate on
changing the Constitution to allow Mbeki to stand for another term. But this has been rejected by the ruling African National Congress's youth league and alliance partners.
"The ANC has taken the position that we don't want to change the Constitution," Mbeki said on Sunday.
"Even when we got that more than two-thirds majority, we said this, that we are not going to use this two-thirds majority fundamentally to alter the Constitution. And that remains our position."
A succession debate recently came to the fore when Mbeki axed his corruption-accused deputy, Jacob Zuma. Zuma is to stand trial on corruption charges this year, and faces a separate charge of rape.
He had been favoured as presidential candidate by some sections in the ANC and its alliance partners.
People, not money
A lack of skills, not money, would be a major obstacle in boosting infrastructure as part of the government's Accelerated and Shared Growth Initiative (Asgi), said Mbeki.
"One of the biggest constraints will not be money to carry out that work, but it will be people," Mbeki said in the interview.
He cited a shortage of project managers for infrastructural projects, and capacity in the government.
There was broad support for Asgi, the president said, and there was continued engagement on the matter with organised labour, business, and other interest groups.
Asgi aims to achieve an average six percent economic growth rate between 2010 and 2014.
On criticism that a large percentage of jobs said to have been created under his government were in the informal retail sector, Mbeki said that was an important part of any economy in the world.
"It would be incorrect to discount that sector," he said.
Asked about government corruption, Mbeki said much of the current service delivery backlogs had more to do with a lack of capacity. There were, for example, not enough engineers for municipal water and sewerage systems.
"But it does worry me a great deal. It seems to me there are many people who enter government for self enrichment."
The matter was receiving serious attention, Mbeki added.
He questioned assertions that much of the current lack of capacity was caused by the loss of skilled and experienced whites under affirmative action.
"I don't think it is so much a matter of attrition as it is an extension of the system of local government."
But moves were afoot to bring retired experts on board by employing them in key posts and using them as mentors.
Mbeki said there would be better supervision of capital expenditure by provincial government in future.
This applied, among other things, to currently inadequate spending on money set aside for agricultural support programmes.
Discussions were continuing with the business sector to establish and rectify constraints to private investment in the economy.
Mbeki said the current labour regulatory framework, criticised in some quarters for inhibiting growth, was correct.
"But we need to look at the impact of the entire regulatory framework on a person who wants to start a small business. It is not only about labour laws."
He criticised the financial sector for demanding guarantees from the government before lending money to aspiring small businesses.
"Shifting the entire risk to government; I don't think that can be correct," the president said.
Problems in Zimbabwe
Turning to Zimbabwe, Mbeki said a new Constitution had been negotiated between that country's ruling Zanu-PF and the opposition Movement Democratic Change (MDC), but its implementation was halted when "new problems arose".
When he reported earlier that the parties were in talks, and an agreement was imminent, he had been asked not to reveal that a new Constitution was on the table, Mbeki said in the interview.
"They were actually involved in negotiating a new Constitution for Zimbabwe," the president said.
"They did, and they completed it."
It had been expected that the parties would then have pursued its implementation themselves, but "new problems arose", Mbeki said.
He was apparently referring to a split in the MDC.
The MDC was in a process of "sorting themselves out", the president said.
"We are watching that. Zimbabweans need to engage and find their own solutions."
'Need to meet' Hamas
On the situation in the Middle East, Mbeki said South Africa would be in discussions with the Palestinian Islamic group Hamas following its recent parliamentary election victory.
An agreement was made with Hamas and the Islamic Jihad movement, before the election, "that we need to meet," he said.
The planned meeting was also discussed with the hitherto ruling Fatah and the Palestinian Authority "and they had no problem with that".
The aim of the talks would be to establish what South Africa could contribute to the Middle East peace process, Mbeki said.
He reiterated the South African government's stance that a two-state scenario, with independent Palestinian and Israeli states living peacefully side-by-side, was the only solution.
Hamas' election victory has been met with caution by Western leaders.
The United States has reportedly refused to deal with a Hamas government unless the group abandoned its stated wish for the destruction of Israel. - Sapa