Premier Jay Weatherill says the State Government is considering a “substantial” plan from the administrators to save Arrium’s Whyalla steelworks.

He wants both the federal Coalition and Labor to commit to a co-investment in the steelworks that will allow it to continue operating.

“We’re seeking to broker an agreement at an early time which will lead to certainty for any new purchaser who wants to come in and invest in Arrium,” he told reporters on Monday.

“I hope that further steps are taken in the next few days as officials meet and then it will be a matter of both Bill Shorten and Malcolm Turnbull, together with the interests represented by the administrators, (reaching) an agreement.

“I think the earlier we do that, the better.”

Weatherill said the Commonwealth had a greater capacity to invest in Arrium but the final share of funding in a potential co-investment would be up for negotiation.

Treasurer Tom Koutsantonis said this week that the State Government was willing to put a “considerable amount of money” on the table to support Arrium.

Lead administrator Mark Mentha said he was confident of securing a federal funding promise before Arrium goes on the market.

“Some of those funds, we’d like to see before June 30 and some over a three-year horizon,” he told AAP on Monday.

“Some are vital for the budget over the next year and we’re selling the business based on the financial year 2017 forecast.”

– with AAP