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.

Premier Daniel Andrews and Energy Minister Lily D'Ambrosio have set out Victoria's terms for agreement on the National Energy Guarantee. Credit:Arsineh Houspian.

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.