Inventor and entrepreneur Sir James Dyson has hit out at plans by Home Secretary Theresa May to expel overseas students as soon as they graduate, warning that it will simply help Britain's international competitors.

Mrs May has said that she wants the Conservative manifesto to include a commitment to compel students from outside the EU to leave the UK once they have completed their degree and to apply for a new visa if they wish to return.

Dyson has its headquarters in Malmsbury and last year Sir James pledged to spend £1bn on research and development, committing the money on 100 new products over the next four years, as well as a further £200million towards additional production lines in south-east Asia so that it can increase its manufacturing capacity to 11 million motors a year.

The spending is on top of a previously-announced plan for a £250m campus expansion at its Malmesbury site, creating 3,000 jobs.

But today, writing in The Guardian, Sir James said the Government should be encouraging the brightest graduates to remain in the country and develop their ideas for the benefit of the British economy.

"Give them our knowledge, allow them to develop their own, and permit them to apply it here on our shores. Their ideas and inventiveness will create technology to export around the world," he said.

"May's immigration plans simply force the nimble minds we nurture to return home and fuel competition from overseas.

"Sending them home with new technology developed here presents very good value to our competitor nations. Instead our education system should be a tool to import the world's greatest minds. And, most importantly, to keep them here, so that it is our economy - and our culture - that benefits."

It is not the first time Sir James's comments have discomforted ministers. During a visit last year by David Cameron to the company's headquarters, he embarrassed the Prime Minister by calling publicly for Britain to leave the EU.