State and federal governments are likely to pay Holden's parent company a "substantial amount" to keep manufacturing bases in Australia.

South Australian Premier Jay Weatherill has foreshadowed a major funding announcement after news the closure of Holden's Australian operations was one option being considered by US parent company General Motors.

Mr Weatherill, Federal Manufacturing Minister Kim Carr and Holden chairman Mike Devereux met with GM executives in Detroit on Monday (US time) to discuss the company's future.

He says the Federal Government will bear the brunt of future funding, which he insists will not be a rescue package.

"We're talking about a very substantial investment from both the Commonwealth and State Government and that's why we want to make sure we get a decent return for that amenity," he said

"It would obviously provide security for the future but we want to make sure that beyond the life of the next model of the Holden it also secures a future for an advanced manufacturing industry in South Australia based on a car manufacturing industry."

He says details of the funding, which he described as a co-investment, are still being determined.

"That's the subject of negotiations. It would undermine our negotiation to disclose that but suffice to say it's a very substantial sum."

Most of Holden's 4,800 workers are based at its Elizabeth assembly plant in South Australia and its Port Melbourne engine factory.

'Bright future'

Mr Devereux says the Government's strategy is the right one.

"There isn't a country in the world that actually has an auto industry, an integrated auto industry, that can design, build and sell a car from scratch that doesn't have one of two things: either large tariff barriers to entry for imports or co-investment," he said.

"Now Australia - I think appropriately so - has taken a very open market approach. It's good for consumers, it's good for prices coming down but it also places pressure on those local manufacturers.

"Countries like Russia, India, China, [have] 40-50 per cent import tariffs.

Messrs Devereux, Akerson, Carr and Weatherill at GM's headquarters in Detroit ( Holden )

"In Australia we have effective tariffs of about 3, 3.5 per cent so if you're not going to have a large tariff wall every country on the planet that plays the game that way has a co-investment attraction type of methodology to get global companies to invest literally hundreds and hundreds and hundreds of millions of dollars in new equipment, plants and technology.

"And that's the path forward for Australia and for South Australia."

Mr Devereux would not speculate on the likelihood of the Elizabeth plant's closure but said it will continue to be a manufacturing base for years to come.

"I'm very confident that with the strong relationship that we currently have and with enough forward planning - and we're talking things three or four years from now - that we'll have a great outcome for both Holden and for the city and for the state," he said.

"We're really not talking about the next three to four years. We're talking about events that will happen in the second half of this decade."

The Federal Government says it expects to have reached an agreement with GM in the next few weeks.

How much?

The South Australian Opposition says it wants to know how much money the Government would invest.

Opposition Leader Isobel Redmond says the State Government has already given almost $36 million to Holden over the past seven years.

"We're all hopeful Holden can stay here, but the reality is we've already put a considerable amount of money, I think some $35 million, $36 million over the years into Holden," she said.

"I would want to know that we're getting some sort of security for the future for jobs not only for Holden but for the ancillary industry of course that are attached to it."

She says the carmaker should consider changes at the plant.

"Whether that's because we manufacture the right-hand drive vehicles or whether it's because we can be the best at producing some new innovative electronic vehicle or whatever it might be," she said.

"I don't want to see us close the door on manufacturing and particularly automotive manufacturing in this state, but I think we do need to take a long-term view as to just where the future might lie."