David Cameron could hardly have chosen a better audience for his call for businesses to "get out there" and campaign against a British breakaway from Europe.
Taking the stage at the World Economic Forum in Davos, the British prime minister urged the CEOs and chairmen of more than 1,000 of the world's biggest companies to campaign for the U.K. to stay in the European Union.
"You can start to look at your own businesses and come up with examples and ideas about the benefits [of EU membership]," Cameron said. "Help to explain and set the context for this vitally important question."
Cameron has promised to hold a referendum on the so-called 'Brexit' question by the end of 2017. He repeated Thursday that he would campaign for Britain to stay part of the EU, provided the bloc of 28 countries and 500 million people is willing to change.
It will be the first time in 40 years the issue has been put to the test, and the U.K. is deeply divided.
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Cameron wants Europe to agree to reform before he sets a firm date for the vote. He wants Britain to have more control over migration, and for Europe to impose less regulation. A meeting of EU leaders next month could be crucial in determining the outcome.
Many of the world's biggest companies have already come out in support of Britain staying in.
Deutsche Bank (DB) has warned it could move business out of the U.K. if the country were to leave the union. Goldman Sachs (GS), Bank of America (BAC) and other major U.S. banks are reportedly considering donating hundreds of thousands of dollars to support the "in" campaign.
A survey of the top 350 publicly traded U.K. companies showed 70% say leaving the EU would damage their business, up from 63% last summer.