Explanation:

Split and merger in AITUC

In 1929, the first split-up of AITUC took place in Nagpur on the issue of the boycott of India's royal labour commission. The Socialists and members of the Indian National Congress (INC) wanted to boycott the royal commission, but moderates wanted to support it. In protest, N. M. Joshi, V. V. Giri, and other moderates left the AITUC.

In 1930, the moderate section set up the All India Trade Union Federation (ITUF) under the leadership of N. M. Joshi. Its first president was V. V. Giri.

In 1931, another split-up in AITUC took place in its Calcutta Session, in which extreme left-wing broke away and formed Red Trade Union Congress (RTUC).

In 1933, Indian Trade Union Federation (ITUF) merged with the National Federation of Labour (NFL) under a new name, National Trade Union Federation (NTUF)

In 1934, Red Trade Union Congress (RTUC) remerged with the All Indian Trade Union Congress (AITUC). As of 1934, there were two central federations AITUC and NTUF.

After the 1937 elections, Indian National Congress (INC) came into power in most provinces. More and more unions got involved in the nationalist movements. Provincial governments passed different legislation to give more recognition to trade unions.

In 1938, V. V. Giri proposed to bring unity between AITUC and NTUF. Thus, NTUC was affiliated with the AITUC

In 1940, the National Trade Union Federation (NTUF) merged with the All India Trade Union Congress (AITUC) in Nagpur, and a united body of trade unions was formed.