Prime Minister Malcolm Turnbull: "The way to take [the double dissolution] option away is for the Senate to pass those bills." Credit:James Brickwood "Hi, my name is Helen and I'm a single parent and mother of three and I'm calling you on behalf of the ACTU," the call begins. "I know how busy you are but there is a serious issue I want to raise with you. I'm incredibly worried about the deal the Liberal Party and the Greens have done that will not just wipe out the small parties in the Senate but may also increase Liberal Party control of the Senate. "The last time the Liberals got control of the Senate they attacked our rights at work. If they got control again it would be worse than last time." A vote on Senate changes is due next week and should pass with the backing of the Greens, the government and Nick Xenophon.

ACTU secretary Dave Oliver wants the Greens to delay changes to Senate voting. Credit:Anna Kucera The changes are viewed as a possible first step towards a double dissolution election that could be predicated on the refusal of the Senate to allow for the reintroduction of the Australian Building and Construction Commission, the so-called "tough cop on the beat" for the building industry. The CFMEU and the wider labour movement is bitterly opposed to the resurrection of the ABCC despite some of the damning evidence of lawlessness that came out of the royal commission into trade union governance. According to the Australian Financial Review, there are 73 CFMEU representatives in front of the courts on different matters. A spokesman for Senator Di Natale said the office had received calls but generally by people confused about why they had been asked to call and some believing that the Greens had asked them to call.

The audio file obtained by Fairfax Media is tagged "CFMEU- 8March16 - ACTU". A spokeswoman for the ACTU confirmed the robocalls are going out on behalf of the union movement and the CFMEU were a key financial backer. "The ACTU does not discuss its financial matters with the media but a CFMEU staffer did organise a part of the business arrangement on the ACTU's behalf," she said. On Friday, Prime Minister Malcolm Turnbull said a double dissolution election - likely to sweep away all but Senator Xenophon and Jacqui Lambie from the crossbench - could be averted if the Senate passes the ABCC legislation and the Registered Organisations bill, which is also blocked. "The only reason to have a double dissolution is to resolve a deadlock," Mr Turnbull said.

"The way to take [the double dissolution] option away is for the Senate to pass those bills." ACTU Secretary, Dave Oliver said: "Unions are deeply concerned about the timing of the Liberal/Green proposals to reform Senate voting and have been voicing our concerns over their potential to open the door to a raft of anti-worker legislation since they became public." "Malcolm Turnbull is using this deal to try and railroad crossbench Senators into supporting anti-worker legislation - such as the return of the ABCC - by directly threatening their seats in Parliament. "Not to mention the potential damage that could be inflicted by a post double-dissolution joint sitting giving the Liberals the opportunity to radically attack workers' rights. "The Greens have been campaigning for Senate voting reforms for almost 20 years - all we're asking is that they wait just a bit longer till the double dissolution window closes."