The company, best known for its vacuum cleaners and other domestic appliances, is working on developing an electric vehicle in the Asian nation
Brexit-backing businessman Sir James Dyson is to relocate the Dyson head office from the UK to Singapore.
The bombshell announcement will mean Dyson is no longer a British registered company and Singapore will become its main tax base.
Billionaire Sir James was one of the loudest business supporters of Brexit at the 2016 referendum and when the talks stagnated in 2017 he urged Mrs May to 'walk away' and embrace leaving Europe.
Despite the firm's insistence the relocation is not to do with Brexit, it is acutely embarrassing to Leave supporters.
And it comes amid mounting concern that a no deal Brexit could be disastrous for British manufacturing - particularly in the motor industry.
Remain supporters lashed Sir James, 71, for 'staggering hypocrisy' and warned it was 'damning for the Government'.
Told by MailOnline the news about Dyson, one Brexiteer Cabinet minister grimaced and said simply: 'Oh.'
It is the second blow Dyson has dealt to Brexit Britain after last year's announcement that it will manufacturer its new electric cars in Singapore, rather than the UK.
In 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. There are huge revenue opportunities in Singapore, China is the poster child of that,' he said.
'The tax difference is negligible for us, we are taxed all over the world and we will continue to pay tax in the UK. We will continue to invest in the UK, in Malmesbury, in Bristol and London.'
Mr Rowan confirmed that Sir James was integral to the decision to ditch Britain.
The decision comes just weeks after Foreign Secretary Jeremy Hunt visited Singapore as he talked up Britain strengthening ties with the country.
Theresa May was warned today the Dyson move was 'damning for the Government' amid mounting concern about the future of British industry
Two of Dyson's senior executives will move to Singapore initially, with the head count to grow over the coming years.
Around 3,500 people work for Dyson in the UK, part of a workforce of around 12,000 worldwide. Relocating the HQ will not cut staffing, the firm insisted.
The company, best known for its vacuum cleaners and other domestic appliances, is working on developing an electric vehicle in the Asian nation.
Leo Varadkar today said Ireland and the UK will have to strike a customs deal to keep the Irish border open if there is a no deal Brexit.
The Irish PM said a new backstop will have to be agreed to honour the Good Friday peace agreement - despite spending two years blocking Britain's bid for a deal.
The comments came after the EU Commission today warned that a no deal Brexit will mean a hard border between Northern Ireland and the Irish Republic.
Mr Varadkar told the Irish parliament: 'Both the UK and Ireland will have an obligation to honour the Good Friday Agreement, protect the peace process and honour our commitment to the people of Ireland and Northern Ireland, that there won't be a hard border.
'We would have to negotiate an agreement on customs and regulations that meant full alignment so there will be no hard border.'
Irish foreign minister Simon Coveney said also warmed that the Irish government 'would not support' the emergence of a hard border.
Just hours earlier the EU commission gave the clearest indication yet that it will insist on physical checks if the UK crashes out of the bloc.
The firm said in a statement: 'An increasing majority of Dyson's customers and all of our manufacturing operations are now in Asia; this shift has been occurring for some time and will quicken as Dyson brings its electric vehicle to market.
'We are now at a point where Dyson's corporate head office will relocate there to reflect the increasing importance of Asia to Dyson's business.'
But 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 about the rising prospects of a no-deal Brexit, which would jeopardise their operations in the country.
Liberal Democrat Layla Moran, a supporter of the Best for Britain anti-Brexit campaign, said: 'This is staggering hypocrisy for Brexit-backing businessman James Dyson.
'It is utterly unbelievable that the business face of Brexit is moving yet another part of his business out of the UK.
'James Dyson can say whatever he wants but he is ditching Britain. This can only be seen is a vote of no confidence in the idea of Brexit Britain.
'Rather than fleeing can I suggest he maybe donates to the final say
