Sir Michael Spicer, chairman of the Euro-sceptic European Research group and MP for Worcestershire West, said that invitations had been issued to some of Britain's largest firms only about a week ago, and 80 business leaders had already endorsed the campaign.
They included Sir Rocco Forte, the hotelier; Sir John Craven, a financier; Sir John Banham, former director- general of the Confederation of British Industry, and Ian McAlpine, director of the building firm, Sir Robert McAlpine.
William Hague, the Conservative Party leader, will address a conference formally to launch the campaign in July.
Sir Stanley Kalms, chairman of Dixons and another of the campaign supporters, told BBC Radio 4's Today programme: "Moving into the Emu would be disastrous for this country. We would immediately lose our monetary control, that is our control over interests interest rates. If we lose monetary control we ultimately lose fiscal control, and if we lose fiscal control then we have lost political control and the UK becomes an offshore part of Europe. A federated Europe is not on our agenda."
He said that the business community was being made well aware of the dangers.