Some 250 business leaders and entrepreneurs backed a cross-party campaign for Britain to leave the European Union on Saturday, as the Vote Leave group said it wants to "make the case that EU membership is holding back British business."
The 250 names, listed in a personal capacity, include Michael Geoghegan, former head of HSBC Group; Tim Martin, creator of the JD Wetherspoons chain of bars; and David Ross, founder of Carphone Warehouse.
"With our growing list of business supporters, Vote Leave will make the case that whilst the EU might be good for big multinationals, for smaller businesses it acts as a job destruction regulatory machine," Matthew Elliott, Vote Leave's chief executive, said in a statement.
"Brussels hinders smaller businesses, particularly those firms who can't afford to lobby Brussels to curry favour," Elliott said. "Jobs, wages and our economy will thrive when we take back control and Vote Leave."
Last month nearly 200 leaders of large businesses backed Prime Minister David Cameron's campaign for Britain to remain in the EU, saying a British exit, or Brexit, would "deter investment and threaten jobs."
Top executives from 36 companies listed on London's FTSE 100 index singed the "remain" letter, including Airbus UK, British Telecom, BP, HSBC, Rio Tinto, Royal Dutch Shell, SABMiller and Standard Chartered.
The Confederation of British Industry, which represents some 190,000 businesses, has also backed Cameron, praising the reform package he agreed with the 27 other EU leaders as "a major step forward."
Britain will hold a referendum on June 23 on whether or not to remain part of the EU.
Eurosceptics inside Cameron's ruling Conservative party have provided the strongest support for the "leave" campaign.