Dyson said that a ventilator he had developed to treat coronavirus patients in response to a government call would ultimately not be necessary in Britain.
The appliance maker was one of a number of companies that responded to a call last month by Prime Minister Boris Johnson to help equip the National Health Service with machines, which help people breathe if they develop severe symptoms.
The company told staff in March that it had received an order from the government for 10,000 of its new CoVent fans and plans to start delivering them “within a few weeks”, subject to regulatory approval.
He had hoped this would happen soon, but the specifications were changed and the ventilator had to be redesigned so that it could attach to the pipes that supply medical gases to hospitals, according to someone familiar with the matter.
The government has been criticized for its management of fan purchases, ranging from too much focus on designing machines from scratch, to the specifications originally released being too basic.
The ministers insisted that the strategy was always a combination of larger imports from abroad, increased domestic production of existing models and encouraging new models that could be quickly produced in the Kingdom -United. Technical requirements have been changed by medical understanding of the virus, officials said.
Progress is being made toward a target of 18,000 fans and the NHS now has 10,800, an increase of 2,600 from mid-March.
A consortium of engineering companies including Rolls-Royce, Airbus and Siemens is helping to increase production of two British fans to fill an order for 20,000 units. Over 250 have been delivered to date.
Both models are the Smiths Medical paraPac transport ventilator, used by paramedics; and an adapted version of a Penlon anesthesia machine that received regulatory approval last week.
Several other teams developing new fans or modified versions of existing fans have also received interim purchase commitments, although it is unclear how many will pass safety tests.
The Cabinet Office, which manages the ventilation program, said that a number of the devices were undergoing regulatory testing and that no decision had been made.
James Dyson, the founder of the company, said that the CoVent device would now be “fortunately” not necessary because demand for fans was lower than expected.
“I have some hope that our fan can still help the response in other countries, but it requires more time and investigation,” he wrote in an email to staff.
Dyson said he would not accept any public money for his ventilation initiative, which was a collaboration with the medical technology consultancy TTP. Sir James said he would cover the £ 20 million spent on the project.
Additional reporting by Peter Foster