The Abbotsford-based company behind the plant, Solar Systems, was placed in receivership in September after failing to attract additional funding to build the $420 million plant.
More than 100 workers owed $4 million in entitlements were made redundant. A public meeting to be held in Fitzroy on Thursday night will call on the Government to guarantee that the plant is built, or risk losing a further 950 potential jobs.
The ''Renewable is Do-able, Green Jobs for Victoria'' campaign was launched when Solar Systems went into receivership. The company needs $50 million to $100 million to make the Mildura solar plant operational. When it was launched, the Federal and State governments pledged $125 million in grants, only a fraction of which have been delivered.
Solar Systems administrator Stephen Longley, of PricewaterhouseCoopers, said a decision on whether the company would be sold or go into liquidation would be made tomorrow week at a second creditors' meeting.
''Save Solar Systems'' campaign spokesman Chris Breen said organisers wanted the Government to immediately intervene to guarantee that the company's Abbotsford factory would remain open, the redundant workers reinstated and the solar power plant built.
''We want the Government to step in and do whatever it takes to make the Mildura solar power plant happen,'' Mr Breen said.
''If Solar Systems folds, no other company in Australia currently has the technological capability to build the plant. If we don't get large-scale renewable energy there, then when and where will we get it?''
One sacked worker, Diamond Creek engineer David Turner, is relying on the Government to ensure the plant goes ahead so he can get his job back. ''We knew the company was trying to raise money but we didn't think the situation was so dire,'' he said. ''The point is the technology is here and we just need a bit more willpower to get it over the line.''
The collapse of Solar Systems, which has been blamed on the global financial crisis, is a significant blow for the renewable energy industry and has cast doubts on a $50 million State Government grant and a $75 million Commonwealth grant earmarked for the project.
The State Government has handed over only $500,000 of its grant to Solar Systems, and none of the federal funding has been delivered.
A spokeswoman for Energy and Resources Minister Peter Batchelor said the Government was working closely with administrators to sell the business.
''Our $50 million was provided to build the solar power station, not for the operation of the company, and the operational matters will be determined by the administration,'' she said.
''The Government is still keen to see a solar power station built.''
The 154-megawatt solar plant was to have produced enough energy to power 45,000 homes, create 950 jobs and save an estimated 400,000 tonnes of greenhouse gas a year.
Solar Systems planned to use photovoltaic solar cells to concentrate the sun's power by 500 times and feed the energy into the national power grid by 2013.
A pilot plant to demonstrate the technology has been completed at Bridgewater, central Victoria, but construction has not begun on the main project.
The project ran into trouble in July when Hong Kong-based energy company China Light & Power (CLP) refused to provide additional funding unless another company stepped in to share the risks. CLP announced a month later that it would write off its $53 million investment in Solar Systems.
Solar Systems investors who could face big losses include tennis great Ken Rosewall, millionaire playboy Adrian Valmorbida, and political and media identities John and Janet Calvert-Jones.