Tomorrow, the Co-operative Group and United Co-operatives will officially merge to create the world's largest consumer co-operative. On the face of it, this mega-merger of the UK's number one and number two co-op societies suggests the highly complex co-op movement, currently split into 30-plus societies, is one step closer to a unified 'super co-op'. But, it seems advocates for such a society, including Peter Marks, the new CEO of the enlarged society, still have a lot of work to do to convince smaller co-op societies. Although smaller co-ops such as East of England and Chelmsford Star wholeheartedly welcome tomorrow's merger, they have no plans to join forces. Smaller societies are unwilling to lose their independence and believe that by sticking to a regional operation they can serve their customers better because they know what makes the locals tick. And through the movement's food buying outfit the Co-operative Retail Trading Group, they are already reaping the benefits of a national retailer. Marks and co will have to use this latest merger to persuade these societies that the movement has more to gain as one.