Malcolm Turnbull has banned his ministers from having sex with their staff, sent Barnaby Joyce on leave and suggested he "consider his position", as the Prime Minister tried to end the embarrassment crippling his government.

Hours after telling Parliament on Thursday Mr Joyce would be taking leave next week and therefore to serve as Acting Prime Minister while the Prime Minister was in the United States, Mr Turnbull announced the ministerial code of conduct had been rewritten to forbid a minister engaging in sexual relations with staff, regardless of their marital status.