A national deal on energy security is hanging by a thread as Labor state governments issue new demands that appear impossible to meet, challenging the Turnbull government to redraft its flagship National Energy Guarantee within days.

Victoria and the ACT will defy the federal government's pleas for consensus, issuing a list of fresh demands designed to protect the national energy policy from any roll-back of renewable energy in the Coalition party room.

The state and territory governments are hardening their stance by insisting on the changes as a condition of their support, exercising their veto power over the national plan at a meeting in Sydney this Friday.

The federal government says its plan would deliver lower power prices, increase the reliability of the grid and cut carbon emissions in line with Australia's Paris climate pledge.

But the Andrews government on Tuesday laid out four tough new demands, including three-yearly reviews of the scheme's emissions target, and a requirement that the emissions target be set by regulation rather than having to win approval in a potentially hostile Senate.