A proposed parliamentary question to Deputy President Jacob Zuma about a meeting with French businessman Alain Thetard is out of order, Speaker Baleka Mbete has said.

The question by Raenette Taljaard (DA) was one of four to be put to Zuma in question time today.

In a letter to Taljaard, which was copied to Zuma, Mbete said: "The issues raised in your question are the subject of a ... judicial process. I wish to advise you that the ... question is out of order ... as it does not comply with the sub judice rule."

"National assembly rule 65 states no member shall refer to any matter on which a judicial decision is pending."

Taljaard said she was concerned about the Speaker's directive and would raise the matter with her party whips this morning.

Eshaam Palmer, parliament's chief legal adviser, said the assembly had the constitutional right to freedom of expression, but because it respected the courts there was a self-imposed rule constraining members from influencing a court's decision.

With acknowledgements to Angela Quintal and The Star.