In April, Ms Ortega successfully challenged a Supreme Court decision to assume the powers of the opposition-controlled legislature, making her the highest official in years to openly break with the ruling party.

She filed a Supreme Court challenge last week to Mr Maduro's plan to elect a legislative super-body known as a constituent assembly, that will have the power to rewrite the constitution and in some cases dissolve state institutions.

The Supreme Court rejected the challenge on Monday.

"The electoral chamber of the Supreme Court of Justice declares that the (challenge) filed by Luisa Ortega Diaz is inadmissible because it is an inept accumulation of pretensions," the court said on Twitter.