Communalism Grows.

Politically there was a degree of unity between Muslim and Hindu leaders after World War I, as typified by the Khilafat Movements Relationships cooled sharply after that campaign ended in 1922. Communalism grew rapidly, forcing the two groups apart. Major riots broke out in numerous cities, including 91 in U.P. alone. At the leadership level, the proportion of Muslims among delegates to Congress fell sharply, from 11% in 1921 to under 4% in 1924.
Muhammad Ali Jinnah became disillusioned with politics after the failure of his attempt to form a Hindu-Muslim alliance, and he spent most of the 1920s in Britain. The leadership of the League was taken over by, Sir Muhammad Iqbal, who in 1930 first put forward the demand for a separate Muslim state in India. The "Two-Nation Theory", the belief that Hindus and Muslims were two different nations who could not live in one country, gained popularity among Muslims. The two-state solution was rejected by the Congress leaders, who favoured a united India based on composite national identity. Congress at all times rejected "communalism"—that is, basing politics on religious identity. Iqbal's policy of uniting the North-West Frontier Province, Baluchistan, Punjab, and Sindh into a new Muslim majority state became part of the League's political platform.
The League rejected the Committee report (the Nehru Report), arguing that it gave too little representation (only one quarter) to Muslims, established Devanagari as the official language of the colony, and demanded that India turn into a de facto unitary state, with residuary powers resting at the centre – the League had demanded at least one-third representation in the legislature and sizeable autonomy for the Muslim provinces. Jinnah reported a "parting of the ways" after his requests for minor amendments to the proposal were denied outright, and relations between the Congress and the League began to sour.
The Muslim League successfully mobilised the religious community in the United Provinces in the late 1930s. Jinnah worked closely with local politicians. However, there was a lack of uniform political voice by the League during the 1938–1939 Madhe Sahaba riots of Lucknow.