The majority of British businesses would vote to stay in the EU in a referendum, a senior business leader said on Monday as he warned that increasing eurosceptic rhetoric risked "shutting ourselves off from the world".
Mike Rake, the president of business lobby group CBI and chairman of telecoms giant BT, told the CBI's annual conference that membership of the European Union was "overwhelmingly in our national interest".
He is the latest business leader to make the case for Europe amid concerns that Prime Minister David Cameron's increasingly hawkish attitude toward Brussels is making it more likely that Britain could leave the bloc.
Opposition Labour party leader Ed Miliband also warned on Monday that Cameron's promise of an in-or-out referendum in 2017 had weakened Britain's influence in the EU.
Opening the Confederation of British Industry conference in London, Rake told the 1,000 delegates that Britain 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," he said.
"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."
"British business will always choose openness," he added, saying that four out of five CBI members would vote to stay in the EU in a referendum.
Rake agreed that reform was needed to make the EU more open, competitive and outward-looking -- changes that Cameron, in his speech to the conference, insisted that he could deliver.
The Conservative leader rejected suggestions that his promise of a referendum -- which would only take place if he wins re-election next year -- was creating uncertainty that was harming British business.
"The worst thing for us to do as a country is to pretend this European debate isn't happening," he said.
"The best thing to do is to get out there, make the arguments, make the changes and then put that to the British people."
In his speech to the conference later, Miliband -- who has refused to match Cameron's referendum promise -- was set to warn that leaving the EU would be a "disaster" and condemn those who "flirt" with the idea.
"A country making ever-more incoherent demands, ever-more isolated from its partners, means we are on the conveyor belt towards exit with no idea how to get off," he will say, according to extracts of his speech.
The Labour leader is hoping his support for the EU will help win back business leaders dismayed by his calls for intervention in the energy market and to break up Britain's big banks.