The move, which would pass the upper house with the support of Labor and the crossbench, would present the government with a dilemma when it reaches the lower house.

Supporting the amendment would potentially complicate the impending lease of 50.4 per cent of Ausgrid, which may be worth more than $10 billion.

Rejecting it would risk souring the government's relationship with Mr Nile, whose support it routinely counts on to get legislation through Parliament.

On Monday, Fairfax Media revealed Mr Nile would demand that Treasurer Gladys Berejiklian include a no-forced-redundancies clause in the electricity company lease contracts.

Mr Nile struck an agreement with the government securing a five-year job guarantee for power workers in return for his support for the privatisation legislation in the upper house.

But Ausgrid has written to the Electrical Trades Union arguing that forced redundancies can be included in a new workplace agreement struck under the Fair Work Act.

Ausgrid needs to shrink its workforce after an Australian Energy Regulator determination cut the amount of money it and Endeavour Energy can charge customers.

The Electricity Network Assets (Authorised Transactions) Act says Ausgrid must retain 3570 employees, down from the present 4100, until June 2020. Endeavour must retain 2100 – roughly its existing workforce after voluntary redundancies.

Removing the option of forced redundancies could mean Ausgrid has to offer higher voluntary packages or redeploy workers instead.

It also makes it difficult for either company to replace existing jobs with contract labour and count them towards the minimum employee figure, which they are allowed to do under the legislation .

On Tuesday Mr Nile said he would be willing to move an amendment to the electricity privatisation legislation to remove reference to the Fair Work Act "to make it watertight".

Labor, the Greens, the Shooters, Fishers and Farmers Party and Animal Justice Party MLC Mark Pearson told Fairfax Media they would support the amendment, meaning it would pass the upper house.

Bids for Ausgrid from Chinese government-owned State Grid Corporation and Hong Kong-based Cheung Kong Infrastructure were lodged on Monday, with business plans due to be presented this week.

The transaction is already the subject of concerns over the potential security implications if State Grid Corporation is the successful bidder.

Independent senator Nick Xenophon has written to federal Treasurer Scott Morrison seeking assurances that advice has been sought from ASIO and Defence about a successful State Grid bid for Ausgrid.

Independent MP Bob Katter has also expressed concerns about selling control of "essential strategic services" to a Chinese government-owned entity.

The NSW government has allowed bids for Ausgrid to be conditional on approval by the Foreign Investment Review Board.