 At the 1905 party convention , August Bebel , who had always favored a stronger role for the SPD @-@ affiliated unions , proposed a resolution requiring all members of the party to join the centralized trade unions for their respective professions . This would have forced all FVdG members to either leave the party or the trade union . The resolution was adopted , and implemented in 1907 . An FVdG survey returned a vote of twenty @-@ two to eight opposing rejoining the centralized unions . This led some of the masons , carpenters , and construction workers in the union to leave the FVdG in 1907 to avoid being expelled from the SPD , saying the organization was " taking a path , which would certainly lead to strife with the SPD and to syndicalism and anarchism . " In 1908 , the SPD 's Nuremberg congress finally voted to make SPD and FVdG membership incompatible . 
