CBI president Sir Mike Rake has warned that the UK faces “isolation” in Europe with barriers to trade, people movement and investment, should the country leave the EU.

Opening the business lobby’s annual conference in London today, Sir Mike said the country faced a choice between two futures:

“One, in which we risk looking inward, shutting ourselves off from the world in the face of inevitable global change and where we reject the power of free and competitive markets to drive progress.

“The other, in which we embrace the openness which has always been the foundation of Britain’s success – to trade, to people, to investment and to ideas from abroad, and of competitive markets at home.”

He said remaining part of the EU was “overwhelmingly in our national interest” and that eight out of 10 CBI members – large and small businesses – would vote to stay part of the bloc.

The UK will head to the polls in six months’ time, with the Tories promising a referendum on EU membership should they be returned to power.

“Amidst by-elections and with the general election just six months away, the political rhetoric is inevitably ratcheting up as the battle for hearts, minds and votes intensifies,” said Sir Mike, adding “we must renew and reaffirm our future as an open and outward looking country”.

The CBI has 190,000 members including businesses of all sizes and in all sectors, together employing around 7 million people.