John Longworth has resigned as director general of the British Chambers of Commerce after accepting his support of Brexit was "likely to create confusion" over the group's official stance, a spokesman for the business organisation said.
It comes after Downing Street denied accusations of involvement with Mr Longworth's suspension from the BCC.
Leader of the House of Commons, Chris Grayling, has labelled the treatment of John Longworth by the British Chambers of Commerce (BCC) "disgraceful".
Mr Longworth resigned after he expressed the view that Britain would be better off outside the European Union, which is in contrast to the BCC's officially 'neutral' position on the referendum issue.
Mr Grayling said Mr Longworth should have been able to campaign for the UK to leave the EU from within the BCC, just like the Prime Minister has allowed current ministers in the government.
Business leader has said he could become a spokesperson for the pro-Brexit campaign after resigning from the British Chambers of Commerce.
Britain's continued EU membership will make it harder to identify terrorists and keep the UK safe in future, a top Tory MP has claimed.
Boris claims if Britain votes to leave the EU "all options are good" as he believes the country will be able to strike new free trade deals.