States and territories are being torn in all directions with calls to immediately sign up to a national energy policy against pleas for them to walk away altogether.

Industry groups are as divided on the policy as the nation’s energy ministers who will meet on Friday for what could be their last chance to sign off on the Turnbull government’s National Energy Guarantee.

Kerry Schott, head of the Energy Security Board and one of the policy’s architects, says if the guarantee isn’t approved in the next week the opportunity will be lost.

‘It’s very possible if we don’t get agreement in the next week or so this is absolutely off the table until the middle of next year and at that point it’s probably gone,’ she told ABC radio on Thursday.

A federal election is due by May 2019.

Melbourne University energy expert Simon Holmes a Court disputes the rush and wants the full modelling to be released so states, territories and experts can test the claims themselves.

The Turnbull government and the ESB say the policy will bring down household power bills by $550 a year through the 2020s.

But Mr Holmes a Court said that was ‘nonsense’ because the electricity component of household energy bills is just $650 a year to begin with.

‘I took a straw poll recently with 16 energy researchers and only one of those 16 thinks there is a likelihood the NEG will reduce prices. At all,’ he said.

The Smart Energy Council wants ministers to reject the policy on the basis it could be changed when the coalition partyroom meets next Tuesday.

‘We don’t have the detail and we don’t know what’s going to be bolted on as part of the pro-coal Monash Group lobby inside the coalition,’ chairman John Grimes said.

‘There’s no reason they can’t give in-principle support to flag that they’re engaged in a proactive way in the process, but there is no way the states can sign up with unconditional support tomorrow. That would be a disaster.’

Energy company AGL has become the latest group to offer strong support for the plan currently on the table.

Chief executive Andy Vesey anticipates progress on new gas and pumped hydro generation projects and battery storage if the policy is settled.

‘While wholesale electricity prices have already begun to fall over in the past 12 months, policy certainty is key to encouraging the additional generation supply that will place further downward pressure on prices and benefit consumers over time,’ he said on Thursday.

AGL’s position backs up the calls of a powerful alliance of employer, industry and farming groups who urged support for the policy in a joint statement this week.

‘There can be no further delays. A decade of policy uncertainty has only resulted in higher electricity prices and a less stable and reliable energy system,” the group including the Business Council of Australia, National Farmers’ Federation and Australian Energy Council said.