In a bombshell announcement, his company revealed it is to move its head office from the UK to Singapore.
It means Dyson, famous for its vacuums and fans, is no longer a British-registered company and Singapore will become its main tax base.
Justifying the move, chief executive Jim Rowan dismissed the idea of Brexit and lower taxes being a motivation.
“The move is nothing to do with Brexit or tax, it’s about making sure we are future proofed.” he said.
The inventor, who made huge a increase in profits after shifting production of his vacuum cleaners to Malaysia from the UK in 2003, also wants it to be easier to hire and fire workers, arguing in 2017 that “not being able to flex your workforce is another big reason why you wouldn’t start or expand a manufacturing business”.
He also said corporation tax should be “eliminated”, adding it is a “very odd thing because there are ways of getting around paying it”.
Labour MP Jo Stevens called the move “shameless hypocrisy” while journalist Kevin Maguire called Sir James a “reckless billionaire”.
James McGrory, director of the Peoples Vote campaign lobbying for a second referendum, said: “It’s alright for billionaires I suppose...”
It is the second blow Dyson has dealt to Brexit Britain after last year’s announcement it will manufacture its new electric cars in Singapore, rather than the UK.
Sir James has been one of the biggest cheerleaders for a no-deal Brexit. Multiple assessments of what this would look like like for Britain suggest it would be far from rosy for most people, with poorest families the hardest hit.
Despite this, Sir James told the BBC’s Andrew Marr in 2017 that Britain should “walk away” from the EU.
He said: “I don’t think it is the government’s fault, I think the problem is the people we are negotiating with.
“I think they are demanding billions and billions to leave is quite outrageous. And demanding it before we have negotiated anything is outrageous.
“I would walk away, I think that is the only way to deal with them.”
At the time, the comments drew a very similar response to today’s.
Having one of Britain’s most successful manufacturers quit the UK comes at a sensitive time, with several car makers including Nissan, Ford and Toyota warning of the risks of a no-deal Brexit, which would jeopardise their operations in the country.
Dyson was keen to stress its commitment to Britain, pointing out that it is investing £200m in new buildings and testing facilities at its campus at Hullavington Airfield.
The company bought the disused airfield two years ago and has already renovated two hangars at the 517-acre site.
The announcement was made alongside Dyson’s full year results for 2018, when profits topped £1bn for the first time.
Turnover rocketed 28% to £4.4bn and profits jumped 33% to £1.1bn, with Rowan pointing to the success of products such as its Supersonic hairdryer.