Britain will gain more from leaving the EU than it will lose, billionaire entrepreneur Sir James Dyson has said.
The inventor said the idea that Britain could not trade successfully outside the EU was "absolute cobblers".
He said the single market did not work because exporters had to adapt products like his to cater for different languages and different types of plugs.
Britain Stronger In Europe said: "James Dyson wanted the UK to join the Euro. He was wrong then and he is wrong now."
Court battle
Speaking to the Daily Telegraph Sir James, who is best known for designing a bagless vacuum cleaner, said the UK "will create more wealth and more jobs by being outside the EU than we will within it".
"When the Remain campaign tells us no one will trade with us if we leave the EU, sorry, it's absolute cobblers. Our trade imbalance with Europe is running at £9bn a month and rising. If this trend continues, that is £100bn a year."
Sir James argued that if, after a vote to leave, the EU imposed a 10% tariff on UK goods, Britain would do the same on imported EU goods. He said that because Britain imported far more from the EU than it exported there, it would bring in an extra £10bn a year for the UK.
The entrepreneur, who is worth over £3bn, also criticised the EU's free movement for not allowing the talented staff he needed to work in the UK.
Sir James has been involved in several battles with the European Court against the EU's energy labelling policy
"We're not allowed to employ them, unless they're from the EU," he said. "At the moment, if we want to hire a foreign engineer, it takes four and a half months to go through the Home Office procedure. It's crazy.
"Why on earth would you chuck out researchers with that valuable technology which they then take back to China or Singapore and use it against us?"
Sir James has been involved in several battles with the European Court against the EU's labelling policy for vacuum cleaners.
"It's a politically motivated court of justice," he said. "Politically motivated to protect vested interests."
But Britain Stronger in Europe accused Sir James of "wanting to have his cake and eat it when it comes to the EU".
It highlighted that in 2000 Sir James had said Britain would be "suicidal" not to join the single currency and that in 2014 he had called for the free movement of people within the EU to be retained.
Sir James's announcement comes as a new poll suggests the Brexit camp has a 10-point lead. The latest online survey of 2,000 people on Wednesday and Thursday by ORB for the Independent put the scores at 55% to 45% in favour of pulling out, after allowing for an individual's likelihood to vote.
Vote Leave has tweeted that it does not believe the poll, adding it thinks the split is closer to 50-50.
In other developments:
- Jeremy Corbynwill make a fresh push to persuade Labour supporters to back keeping Britain in the EU. Amid questions over his commitment to the cause, he told Channel 4's The Last Leg that he was "not a huge fan" of the EU but was 70-75% in favour of staying
- A group of 13 Nobel prize-winning scientists have urged voters to back Remain saying leaving the EU was a "key risk" to the future of British science
- The Remain campaign has also been backed by some of Britain's largest developers and house builders who say a vote for Brexit will make the housing crisis worse
- Nigel Farage says he thinks the Leave campaign is on course for victory in the EU referendum with its "upbeat" message about life outside the EU
Source: bbc.com