Johannesburg - In the last three years the Cosatu membership has dropped by 324 835.This was according to a copy of the federation's draft organisational report by acting general-secretary Bheki Ntshalintshali to be presented at its national congress next week.Cosatu currently had a membership of 1 868 193, less than half the four million target it had set out in its 2015 plan.The plan had originally set the target by 2009, but later adjusted it to 2015.In November 2014 Cosatu expelled its biggest affiliate, National Union of Metalworkers (Numsa). At the time Numsa had 320 000 members.Last week Numsa announced it had decided not to appeal its expulsion. Since Numsa's expulsion, Cosatu has admitted the Liberated Metalworkers Union of South Africa (Limusa), with 7 771 members, as an affiliate.Currently the National Education, Health and Allied Workers' Union (Nehawu) is its biggest union with 277 317 members followed by the National Union of Mineworkers (NUM) - 270 649, South African Democratic Teachers Union (Sadtu) - 248 556, Police and Prisons Civil Rights Union (Popcru) - 154 008 and South African Transport and Allied Workers' Union (Satawu) - 152 254.Cosatu is currently dominated by public service unions.'You are in trouble'Earlier this year, ANC secretary general Gwede Mantashe, himself a former unionist, warned against this."Once you have a federation dominated by the public sector, you are in trouble," he told the NUM congress in June."We should have industrial unions building themselves, as well as putting [it] on our shoulders to help ... NUM to be strong enough to deal with [the Association of Mineworkers and Construction Union]."NUM had seen a big drop in membership numbers since Amcu's formation. Cosatu's organisational report states NUM has lost 39733 members since 2012.Infighting and factionalism has caused several breakaway unions in the past few years. In the report Cosatu said there were internal union organisational and administrative weaknesses.Cosatu affiliates were experiencing several challenges including a significant decline in membership numbers in some unions.Another challenge was unions getting involved in business by establishing investment companies. This had created contests, competition and corruption.The rise in benefits and privileges for union leaders had also caused a growing social distance between union leaders and workers, while the internal leadership battles, which had pitted leaders or factions against each other, had also plagued the union.Lastly, there were issues of poor governance and administration practices and generalised corruption.