Deputy Labor leader Tanya Plibersek says the opposition is keen to work with the government on any policy that reduced carbon pollution, brought down power prices, and provided certainty.
"But from the eight pages of detail that we have, this policy has hairs all over it," she told ABC radio on Thursday.
Frontbench colleague Tony Burke says the national energy guarantee might be something Labor could support.
"It may well be that what we have in front of us is an emissions intensity scheme managed by the energy retailers rather than managed by the government," he told Sky News.
Energy Minister Josh Frydenberg didn't mince words when asked whether the government plan could be interpreted as anything like Labor's carbon tax.
"Two letters: NO," he told Sky News citing advice to the government from the Energy Security Board which made it explicitly clear the NEG was not a carbon price, tax or subsidy.
The government's plan prompted a hostile response from Labor states when it was released on Tuesday.
The government has been set a deadline to provide more detail after the Senate called on Mr Frydenberg to provide documents and detailed modelling by 12.45pm on Thursday.
The Senate order comes as Prime Minister Malcolm Turnbull continues his blitz to convince voters, industry and state governments of the benefits of his plan.
It was time to have energy generation technologies on a level playing field and see the best projects win, he told a business breakfast in Canberra.
"If you can deliver reliability and lower emissions by upgrading older coal- fired power stations go for it," he said.
"If you can do it by having wind and pumped hydro go for it. Let them compete."
The government argues the national energy guarantee will reduce household bills by an average of $110 to $115 a year over the period between 2020 to 2030.
However, the Greens dismiss it as a "half-arsed policy designed to save Mr Turnbull's bacon".
The policy has been met with a variety of views from within the coalition.
Nationals MP George Christensen is planning to launch a public campaign to get a coal-fired power station in north Queensland, arguing the new policy needs to be broad enough to cater for coal.
The Tasmanian Liberal government says the policy needs to encourage more renewable energy, which not only cuts emissions but creates jobs.
Mr Turnbull says he's aiming to deliver a triple bottom line - affordable and reliable energy, while cutting emissions.