The Democratic Alliance (DA) on Saturday welcomed the launch of Agang SA, led by Mamphela Ramphele.
"The DA welcomes any development in South Africa which hastens the realignment of politics in our country," spokesperson Mmusi Maimane said in a statement.
"Those of us who still believe in the dream of the rainbow nation need to stand together in order to make it a reality … It is equally important not to split the electoral vote to the point where opposition politics becomes ineffective."
He said a weak and divided opposition would not benefit or improve the lives of South Africans.
The launch of a new political party is another step in building a new majority in South African politics, Maimane said.
"What South Africa needs is a strong and growing alternative which can govern well and deliver opportunities for all South Africans."
Ramphele officially launched Agang SA at the Tshwane Events Centre in Pretoria west on Saturday.
The former activist and businessperson lashed out at the African National Congress-led government.
She said accountability begins with the president of a country.
'Steal money meant for RDP'
"We deserve to have a president who knows that it is wrong to steal money meant for RDP houses to build himself a R205-million palace," Ramphele said.
"We have a right to know what kind of business is being done between officials, their families and the government."
She said government was destroying the country's economy and was setting an "appalling" example that others were following.
More than a thousand people, mostly dressed in white T-shirts with Agang SA printed on them, listened intently and cheered as Ramphele spoke about the problems facing South Africa.
In the past five months Ramphele visited communities around the country listening to peoples concerns. – Sapa