A survey by the British Chambers of Commerce found that over three quarters of firms back a proposed referendum on the UK's membership of the European Union.
Prime Minister David Cameron has promised the decisive in/out vote in 2017 if his party, the Conservatives, returns a majority to the House of Commons at the next general election.
Cameron insists he wants to remain in the EU, but on renegotiated terms with more powers transferred back to the UK parliament.
BCC's EU Business Barometer, which surveyed 3,906 British businesses, found that 77% back a referendum. Most back the UK to remain in the EU, however, with 61.4% saying renegotiated continued membership would be the most positive outcome for them.
"These results show that British businesses remain determined to see a recalibrated relationship between the UK and the rest of the European Union, with more powers exercised from Westminster rather than Brussels," said John Longworth, Director General of the BCC.
"Our quarterly survey shows that businesses reject both the Europhile dream of further integration and the Europhobe dream of a complete exit from the EU, provided a satisfactory renegotiation is achieved.
"For the quiet majority of companies, the status quo is not an option. Ministers must pursue reform and renegotiation as a priority."
The 500 million citizen EU, which has 28 member states, accounts for around half of all the UK's trade.
Critics say its institutions are cumbersome, undemocratic and expensive bureaucracies that erode national sovereignty and burden businesses with stringent, unnecessary regulations.
Proponents of remaining in the EU say it is a substantial, competitive trading bloc that wields tough negotiating power across the world, from which the UK benefits by being a part of it. They also say policies such as the free movement of labour are vital to the wellbeing of the UK economy.
Richard Ottaway, the Conservative chairman of parliament's Foreign Affairs Select Committee, has warned that an EU exit would spark a trade war where punitive tariffs and barriers would be imposed on the UK.
"What's the alternative? Outside the EU, negotiating our own terms of trade? Be an independent sovereign nation, calling the shots on our own terms, like Norway and Switzerland?" said Ottaway.
"It sounds attractive, but Norway and Switzerland don't call the shots. They pay billions every year for access to the single market."