LSSP thus became the Ceylon section of BLPI. Through the BLPI, the Lankan Trotskyists attained their formal membership in the Fourth International. The Ceylonese Samasamajists who went to India participated actively along with the Bolshevik Leninist Party, in the struggle for independence that commenced in August 1942 in India. It was generally realised that the impending open revolt against imperialism in India was going to be decisive for the future not only of India but of Ceylon as well. Their property and assets back home were confiscated and P.A.E. Perera (publisher of the “Samasamajaya”) died in India, others were eventually arrested. Only Colvin R. de Silva, Leslie Goonewardene, Vivienne Goonewardena and Selina Perera succeeded in evading arrest up to the end   During the war, there was a split in the movement. Perera and Philip Gunawardena opposed a merger into the BLPI and formed the 'Workers' Opposition'. After the war, they reconstructed LSSP as an independent party. Members of the other section, formed out of the exiled BLPI nucleus, effectively maintained a separate party, the Bolshevik Samasamaja Party. The latter group functioned as the Ceylon section of BLPI and was led by Colvin R de Silva, Leslie Goonawardena and Edmund Samarakkoddy. The relation between the two groups was often antagonistic. The BSP accused the LSSP of 'organisational Menshevism'. The LSSP accused the BSP of being introvert doctrinaires. LSSP wanted to build a mass-based party, whereas the BSP concentrated on building a cadre-based (revolutionary) party. On 25 October 1945 fist-fights broke out at between the two groups at a meeting of the BSP. The LSSP and the BSP were both at the helm of the strike waves that occurred in the post-war period. In 1946 there was a brief reconciliation between the two factions. At the general election of 1947 the LSSP emerged as the main opposition party, with 10 seats. The BSP obtained 5 seats. They also had the support of the Ceylon Indian Congress (CIC - which later became the Ceylon Workers' Congress) of Natesa Iyer, which had 6 members in Parliament and of various independent members. However, SWRD Bandaranaike and his Sinhala Maha Sabha backed the newly formed United National Party (UNP), which was thus able to form a government under DS Senanayake.