Helius bosses have had to delay plans to open a similar plant near Bristol after problems raising the money needed.
Now councillors in Southampton say the £300m wood-fuelled plant planned for the Western Docks should be shelved so city residents are not “left in limbo”.
Last night company bosses insisted they were pressing ahead with plans for the 100-megawatt (MW) Southampton site regardless of the delays at Avonmouth.
It comes as a scathing Government report questioned biomass as a viable green fuel source and claimed it is potentially more polluting than fossil fuels.
Helius says the Southampton plant will be capable of producing enough energy to power 200,000 homes and save the equivalent of 470,000 tonnes of carbon dioxide annually.
It would be a similar size to a 100MW Avonmouth site which has already been granted planning permission.
The firm had aimed to secure funding for that project by last month.
But in a statement released in the company’s interim reports, chairman John Seed progress has “proved more difficult” and added: “It remains our aim to finalise all contract terms, along with the financing for the project, later in the year at which point we expect to secure development fees, which are necessary to provide the working capital required to meet its longer term development and corporate costs.”
A spokesman refused to confirm whether this also delays the Southampton project.
But furious campaigners and politicians have accused them of leaving residents in “limbo”.
Campaigners march through Southampton against the proposed biomass plant.
“It’s been so much time since the pre-consultation without an application and it’s leaving this hanging over the people of this city.”
Millbrook ward Labour councillor Asa Thorpe added: “This is like a Sword of Damocles hanging over the people of Millbrook. It’s causing worry for hundreds of people.”