Politicians must do more to help renewable industries succeed, a director of Vivergo Fuels has said.
The company's plant at Saltend produces bioethanol, a petrol additive made from wheat.
Government targets say 10 per cent of all transport fuel must come from sustainable sources by 2020.
At the moment, the figure is more like 4.75 per cent, much lower than what was expected.
Rick Taylor, Vivergo commercial director, said: "We've designed this for the market we were expecting and at the moment, we're not seeing that happen. We're looking for support from the UK Government to keep this moving.
"We would have hoped to be a couple of percentage points higher and at least as a minimum know what the trajectory looks like ahead.
"The difficult bit at the moment is there's no trajectory from today to 2020."
Vivergo, a £350m joint venture between BP, AB Sugar and chemical firm Du Pont, distills alcohol from grain.
It is then mixed with traditional fuel so cars become greener and when at full capacity by the end of the year, the plant will generate enough to replace the CO2 emissions of 180,000 vehicles a year.
Wheat is also fed to livestock. Mr Taylor said the slowdown was partly due to a debate over whether diverting some crop for fuel use would make life harder for farmers.
At Saltend, leftovers from the bioethanol process are used for making animal feed pellets, meaning the problem does not apply.
The plant will produce 500,000 tonnes of pellets a year when fully operational and is already their largest producer in western Europe.
Mr Taylor said: "We're engaging with politicians at the moment and telling them it's not food versus fuel, it's food and fuel.
"We're not taking this wheat away and making it disappear – we're creating two very good products.
"We've done our part. We've built the place and we need the market to continue to develop and deliver the greenhouse gas savings it was designed to."
Vivergo made a £50m loss last year, according to accounts published earlier this month.
However, the same period also saw continued support from its backers, with AB Sugar and BP each putting in an extra £20m.
Part of the loss was down to developing a large-scale and largely untested process, Mr Taylor said.
He said: "Any start-up business expects to have a tough time in the first couple of years and we're no different.
"It's a process and you know you will hit some challenges along the way."
At full steam, Vivergo will be producing 420 million litres of bioethanol per year from vast quantities of wheat.
With such huge numbers involved, it is inevitably prey to changing commodity prices.
Short-term falls in the value of bioethanol and feed have had an effect.
Mr Taylor said: "The ethanol market towards the end of last year came down significantly.
"There was a lot of ethanol imported into Europe and a lot of ethanol stored and that continued a little bit into this year.
"It's a normal commodity market. These things happen, prices move around and the trick is to try to manage your way through."
Wheat prices have fallen slightly this year due to a British glut, which has also brought animal feed values down.
These kinds of fluctuations are normal and have little effect on Vivergo's long-term future.
As long as bioethanol demand continues, Mr Taylor is sure that the future remains bright.
He said: "It's still really exciting. We're not going to sit back – there's still lots and lots of work to do."
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