John Longworth has stepped down as director-general of the British Chambers of Commerce (BCC) with immediate effect.
Longworth was suspended last week for expressing support for a Brexit. He told Sky News that "the UK would be better off taking a decision to leave the European Union".
The BCC said the resignation was agreed mutually between Longworth and the group's board "and there were no external factors involved". The organisation said it recognised that Longworth's "personal view on the referendum is likely to create confusion regarding the BCC’s neutral stance going forward".
"All representatives of the BCC have the right to personal and political views on the key issues of the day," the group said. "However, they are not expected to articulate these views while acting in their professional capacity, as their views could be misconstrued as representing the position of the organisation as a whole."
Adam Marshall is to take on the role of director-general on an interim basis until a permanent replacement is appointed.
“The British Chambers of Commerce is a non-partisan organisation, and as such, decided not to campaign for either side ahead of the European referendum," the BCC added.
"Its neutrality in the referendum debate reflects the real divisions that exist in business communities across the UK."