The "Stop Zuma" campaign denied the African National Congress (ANC) a two-thirds majority in the recent elections, Democratic Alliance (DA) leader Helen Zille wrote in her weekly newsletter on Friday.

"The fact that the ANC failed to get its two-thirds majority is a direct result of the DA's drive to 'Stop Zuma'."

The "Stop Zuma" campaign was launched in response to what Zille termed the extent of the ANC's plans to change the Constitution and entrench its powers.

She said these intentions were clear from a draft Constitutional amendment which showed that the ANC wanted to reduce municipalities to administrative arms of central government.

"Some (analysts) said that the ANC would not change the Constitution because it had not done so in the past," she wrote.

Zille said the analysts ignored the fact that the Constitutional amendment appeared in the government gazette in the same week as the "Stop Zuma" campaign was launched.

In her weekly letter Zille said the DA had achieved a "historic result" in the past elections.

"We now have the support and momentum to win towns and cities across the country in the 2011 local government elections, and to form the core of an alternative government nationally in 2014.

"We now have 67 Members of Parliament in the National Assembly (up from 47), and we will be allocated a further ten seats in the National Council of Provinces," she wrote.

In the April 22 elections the ANC received 65,9% of the vote, the DA received 16,66% and the Congress of the People received 7,42%.