The Soulbury constitution came into effect in 1946. In trying to cobble an all-party cabinet inclusive of the Tamils, led by G. G. Ponnambalam, the Sinhalese nationalist groups led by S. W. R. D Bandaranaike, the Kandyan Sinhalese, Senanayake had to find a compromise formula. The 1947 elections had returned six representatives from the Ceylon Indian Congress (CIC), based on the votes of the franchised Indian workers and Hill Country Tamils. Although this worried the Kandyans, the main reason for Senanayake and others to review their attitude to Indian workers was the growing threat of Marxist infiltration into estate trade unions. In this he had won the concurrence of G. G. Ponnambalam for the second citizenship act, which required ten years of residence in the island as a condition for becoming citizens of the new nation. Senanayake, who had been very favourable to easy citizenship for Indian workers had increasingly modified his views in the face of Marxist trade union activity. The Bracegirdle affair was regarded as the harbinger of such dangers. The fear of left-wing politics began to grow in the minds of Sri Lankan politicians of the era. The colonial government responded to the agitation of the leftists by imprisoning N. M. Perera, Colvin R. de Silva and other left leaders. Anti Marxist feelings were shared by the mainstream Sinhalese and Tamil leaders alike. (, Ch. 36). The criticism in the house was levelled by Tamil members of the upper chamber (senate), like Senator Natesan, who pointed out that Senanayake had supported the franchise of the Indian Tamils till recently, and had "caved in" more recently.