Business Sees Risk of British Exit From E.U. LONDON - The leader of Britain's biggest business lobby on Monday issued a stark warning of the growing risk that the country would leave the European Union and urged often-subdued British business executives who do favor staying in the bloc to speak out in a robust riposte to increasingly vocal Euroskeptics. In a clear illustration that business leaders are alarmed by the mushrooming debate over Britain's future in Europe, the president of the Confederation of British Industry reiterated how strongly the country's commercial interests were intertwined with those of continental Europe. "If we are to avoid an exit vote in any referendum," the group's president, Roger Carr, told the confederation's annual conference in London, "it is essential that the voice of British business is loud and clear in extolling the virtues of future engagement - not as a reluctant participant but as the linchpin of our wider global trade ambitions." Emphasizing that Europe remained the market for half of all British exports, Mr. Carr added: "Whatever the popular appeal may be of withdrawal, businessmen and politicians must keep a bridge firmly in place. As countries of Europe bind together in pursuit of salvation, we in the U.K. must work harder to avoid the risks of isolation. In the spreading discussion about Britain's future in Europe, Prime Minister David Cameron has said he wanted to renegotiate the terms of British membership in the European Union and focus it more around the single economic market. The outcome of that negotiation could be put to the voters, possibly in a referendum, Mr. Cameron has said. His offer is intended to address the mounting sentiment in his Conservative Party, normally an ally of big business, that Britain might be better off outside the European Union, which has never gained wholehearted backing in Britain. After almost three years of crisis for the euro, used by 17 of the bloc's 27 members, there is more discussion than ever of a possible British exit from the Union. Mr. Carr, the chairman of the energy company Centrica, is also on the advisory board of Business for a New Europe, which campaigns for continued British membership of a restructured European Union. Mark Hadley, a spokesman for the Confederation of British Industry, said Mr. Carr's speech reflected the policies of the confederation, which is Britain's biggest business lobby. This position points to a potential problem for the Conservatives, with Mr. Cameron's more detached stance on the European Union provoking significant tensions with traditional business supporters. Talks this week on the European Union's next budget are likely to increase friction between Britain and European partners. Addressing the confederation conference, Ed Miliband, who leads the Labour Party, sympathized with the alarm over Britain's role, saying he "will not let Britain sleepwalk toward exit from the European Union." He added: "Increasingly we see Euroskepticism on the rise among the British public. We see cabinet ministers in this government openly calling for Britain to leave. Mr. Miliband did not mention that his party recently exploited divisions over Europe by aligning with Conservative hard-liners to press for cutting the European Union's budget. Mr. Cameron, in his speech to the conference, a fixture for decades for political leaders, underscored the global reach of British business. His foreign policy has put a new emphasis on the need to seek new markets in the emerging economies, where growth is likely to exceed that of Europe in the coming years. Yet Britain still exports around as much to Ireland, which is part of the euro zone, as to China. "Europe is the bedrock of our international trade," Mr. Carr said. It should be viewed as the launch pad from which our global trade can expand, not the landmass from which we retreat. Phillip Souta, director of Business for New Europe, said Mr. Carr's comments reflected wider concerns within British business. "Business leaders are reluctant to get into issues that look and smell political," Mr. Souta said. But saying that we belong in the E.U. is something I believe people will be saying more over the coming months. An opinion poll of business leaders by Ipsos MORI, commissioned by Business for New Europe in 2011, showed that 33 percent said they strongly agreed that a British exit from the European Union would damage business, 40 percent that they tended to agree, 14 percent that they tended to disagree, 6 percent that they strongly disagreed and 6 percent that they neither agreed nor disagreed. Against the backdrop of public opinion skeptical about the European Union, the voice of British business is likely to play a crucial role in any referendum. British businesses, however, are far from united while groups critical of the bloc have received significant financing from business figures. In general, bigger companies that trade internationally tend to have a bigger stake in E.U. membership than smaller ones that operate solely in Britain and sometimes see the European Union as a body that imposes costly regulation. The UK Independence Party, which wants Britain to leave the European Union, said Mr. Carr's comments reflected the views of the "corporate, rent-seeking class." Roger Helmer, the party's energy and industry spokesman, said that "the regulatory burden imposed by the E.U. is helpful for big business but devastating for small businesses." Though small, the party has gained enough momentum to threaten the seats of dozens of Conservative lawmakers in future elections. That threat has increased pressure on Mr. Cameron to take a tougher line on the European Union.