The electric vehicle company which was backed by David Beckham said it had stopped operating.
Lunaz, based in Silverstone, said the decision was due to the “delay” in banning the sale of petrol and diesel vehicles.
Last year, Prime Minister Rishi Sunak said a planned ban was being pushed back five years from 2030 to 2035.
The company’s arm converting bin lorries went into administration last week.
Lunaz said in a statement it was “currently restructuring to adjust its business and operations in response to shifting market dynamics”.
It said: “These are caused by delays to the legislative requirement for fleets to transition to zero-emissions vehicles.
“All operating entities of the company have stopped operations with an intent to restart under a new structure to meet current and future demand for the company’s passenger and commercial vehicle products.”
The BBC understands staff were told to go home and not return.
An employee, who wanted to remain anonymous, said the company had brought in new staff as recently as two weeks ago.
He told the BBC last week staff were “called into a room and told that they had not hit their targets and so investors had pulled out” and they would all be made redundant.
The firm filed to change the name of the bin lorry company from Lunaz Applied Technology to App Tech Productions on 13 March.
Buckinghamshire Council, which had a contract with the company to convert a bin lorry, said it was “disappointed” to hear about operations ceasing.
Steven Broadbent, deputy leader of the Conservative-led authority, said: “We are currently in discussion with them on the impact that this will have both on the agreement we have with them to transition one of our refuse vehicles to an electric variant, and for the Buckinghamshire economy.”
The company also had a deal with Biffa to convert 10 lorries.
Anthony Holley, Biffa’s fleet and facilities director, said: “We remain committed to growing our net zero fleet as part of wider plans to decarbonise our operations.”
He added the company would be “continuing our work with the Lunaz Group when operations for its commercial vehicle products recommence”.
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