The Federal Government has secured passage through the Senate of its legislation to split Telstra's wholesale and retail operations.

It allows for Telstra's retail and wholesale arms to be separated, which is a key plank in the establishment of the Government's $35.7 billion National Broadband Network (NBN).

The legislation passed the Senate by 30 to 28 votes after days of protracted and angry debate with the support of the Greens and independent senators Nick Xenophon and Steve Fielding.

Communications Minister Stephen Conroy says the Government has achieved historic reform in Australia's national interest.

"This legislation paves the way for a more efficient rollout of the NBN," he said.

The Opposition is staunchly opposed to the NBN and unsuccessfully sought to delay passage of today's legislation until next year.

Last week the Coalition failed to pass a bill in the Lower House to refer the NBN to the Productivity Commission for scrutiny. It also wanted a cost-benefit analysis to be conducted.

Similar moves in the Senate by the Coalition today, as well as an attempt to put off the vote until late this afternoon, also failed to gain support.

The Senate was due to rise for the summer break yesterday but the Government extended sitting hours into today to ensure the vote was taken this year.

The House of Representatives will return to Canberra to sit on Monday to pass amendments made to the bill.

Two bills which set out the regulatory framework of the NBN have been introduced to the Lower House and will be debated next year.

On Wednesday Prime Minister Julia Gillard was forced to release a summary of the NBN business plan in return for Senator Xenophon's support for the bill.

The crossbenchers were arguing that they should not be forced to vote for the bill without first seeing the business case for the network.

Telstra shares were down 4 cents to $2.84 by 1:28pm (AEDT), but they have been down all day so far.

The move to split Telstra will still require the approval of Telstra shareholders.

Senator Conroy said he was confident shareholders would support it once more financial details about the NBN were released.

"You'll see there's very significant benefits to Telstra shareholders in agreeing with the deal," he said.

Greens Senator Scott Ludlam says the Greens will be scrutinising the legislation.

"We'll be going over that with a fine-tooth comb," he said.

Senator Ludlam says the reform is "very much overdue".

"We've seen a very out-of-balance and anti-competitive telecommunications market," he said.

"We were really happy we were able to secure the reform where it will be made much more difficult to privatise NBN Co in the future."