Six New National Party members said on Tuesday that they would join the ranks of the African National Congress when the floor-crossing period opens on September 1.
They are Health MEC Pierre Uys, Agriculture MEC Cobus Dowry, and Joyce Witbooi who is a member or the provincial legislature, as well as Freddie Adams of the National Council of Provinces, and Carol Johnson and Karel Greyling, both NNP MPs in parliament.
This is seen as a blow to Democratic Alliance hopes of taking control of the provincial legislature with the help of minority parties.
Although provincial ministers were not expected to cross the floor to the Democratic Alliance, the fact they intend to join the ANC means the DA has to collect even more supporters from other parties if it is to have a hope of power.
And ANC provincial secretary Mcebisi Skwatsha indicated on Tuesday that more politicians were due to cross to the ANC.
Skwatsha said he hoped this announcement would end speculation that the provincial government would fall to the DA and that Western Cape premier Ebrahim Rasool would be ousted.
"We need three to have a majority in the provincial legislature. We have that three. We are definitely expecting no dissent from the ANC. There is no way the provincial government is going to fall," said Skwatsha.
He said the six NNP members had served the organisation at various levels and would bring "valuable experience and expertise" with them.
Rasool said dissent from the ANC was "absolutely difficult" in the ANC, both politically and technically. "The ANC is difficult to leave. I cannot recall anybody leaving. The DA would need at least 10 percent or more of us to leave."