The Social Democrats gained a rapid boost when, shortly after their formation, Paddy Webb and James McCombs won by-elections and entered Parliament. They joined with John Robertson, who won a seat in the 1911 election as a Labour candidate bringing the Social Democrat caucus to three. Later the same year, however, a controversial strike broke out among groups of dockworkers and miners. Moderates in the union movement considered the strike ill-advised and dangerous, while radicals strongly supported it. The strike was heavily suppressed by the government of William Massey, and the United Federation of Labour was left broken and disorganised. The Social Democrats, still closely linked to the United Federation of Labour, were plunged into disarray, with three of the party's leaders, Harry Holland, Peter Fraser and Bob Semple, being jailed for their roles in the strike.