Labor is backing a move to extend powers allowing federal law enforcement agencies to snoop on encrypted messages to state anti-corruption bodies.
Controversial encryption-busting powers rushed through parliament late last year will be extended to federal and state corruption watchdogs.
Legislation was debated in the Senate on Thursday which paves the way for anti-corruption bodies to get the same powers as other agencies to compel technical assistance to access electronic communications.
The amendments, which are supported by the opposition, will also ensure an independent review of the bill occurs within 18 months of it passing parliament.
Labor backed the Morrison government's encryption bill in December on the condition the government would agree to fully implement a parliamentary committee's recommended changes.
But shadow attorney-general Mark Dreyfus has accused the government of breaking the agreement to improve the laws, which allow authorities to intercept Facebook, WhatsApp and other encrypted messages.
"It is not tenable to argue, as the government continues to argue, that its amendments largely implemented the committee's 17 recommendations," he told parliament on Tuesday.
"No reasonable person accepts that."
Labor successfully changed the bill with the support of the Greens and the majority of crossbench senators to provide safeguards around the "systemic weakness" provisions which tech giants have railed against.
The opposition will pursue a series of other amendments when debate on the bill resumes.