Updated: A motion in the Senate today from Liberal Senator Cory Bernardi to disband Labor-Greens majority Senate Select Committee for the NBN and replace it with a joint committee comprising of a majority of Coalition MPs has been delayed.

The Senate Select Committee was established last year following the election of the Coalition government. It was designed to replace the Joint Parliamentary Committee that had been led by former Independent MP Rob Oakeshott. There are three Labor senators, three Coalition senators, and one Greens senator on the committee, meaning the government is in the minority on the committee.

As a result of the Labor-Greens majority on the committee, the hearings have been dominated by former Communications Minister Stephen Conroy probing his former department and the new NBN Co executives over the details of the National Broadband Network changes since the election, and the reviews conducted into the NBN, as well as the company's strategic review.

To break Conroy's grip on the committee, the government had sought to re-establish the joint committee last year, but lacked the numbers in the Senate to get it through. At the time, the opposition extended the life of reporting.

Now with a new Senate sitting as of July, the government will be relying on support from key cross-bench Senators as well as the Palmer United Party to disband the Labor-Greens Senate committee, and establish a new joint committee chaired by a government MP, with a majority of Coalition members.

The motion was expected to pass the Senate on Wednesday, but ZDNet understands that some of the cross-bench votes the government would have relied on to pass the motion today pulled their support for the motion.

The motion was delayed until Thursday, but ZDNet understands it is unlikely to be put to the Senate before parliament rises. This would mean the motion will be delayed until at least the Spring sitting beginning in late August.

The new joint committee that the government wants to establish would have nine members from both the House of Representatives and the Senate, consisting of five Coalition MPs, three Labor MPs, and one Independent MP.

A spokesperson for Communications Minister Malcolm Turnbull told ZDNet that the new committee will allow the Labor's shadow minister to take part in parliamentary review of the NBN.

"The re-establishment of a Joint Parliamentary Committee to oversee the NBN will allow Labor’s shadow minister Jason Clare to be involved in scrutiny of the project," the spokesperson said.

"It is designed to restore an orderly supervision of the NBN with participation of both houses of parliament."

A spokesperson for Clare told ZDNet that with a government majority on the proposed committee, Turnbull would avoid scrutiny over the NBN and broadband reviews.

"Malcolm Turnbull is trying to kill scrutiny of the NBN. Regardless of what you think about the NBN, this is the biggest infrastructure project in Australia. It involves $30 billion of taxpayers money and it needs to be properly scrutinised," he said.

"It's no coincidence that Malcolm Turnbull is trying to kill this committee before the Vertigan report is released."

The chair and members of the committee have yet to be decided, but the motion is being moved by current NBN committee deputy chair Liberal Senator Cory Bernardi.

It comes as today a report into the NBN roll-out in Tasmania is also due to be tabled in the Senate, and Turnbull is set to release the first part of the Vertigan review into broadband in Australia.