The ANC has downplayed Baleka Mbete?s decision not to be sworn in as an MP.

The former deputy president?s absence from the National Assembly chamber when Jacob Zuma was elected president raised some eyebrows.

The ANC said it was a legal difficulty that prevented her from taking the prescribed oath.

ANC spokesperson Jessie Duarte said Mbete was not sworn in after the ANC took legal advice.

"The advice that she was given is that she can?t be the deputy president of the third Parliament as well as an MP in the fourth, so that's the issue."

Mbete remains deputy president until Saturday when Zuma will be sworn in.

It was unclear what role she would play in the new administration.