In March of 1927, Jinnah convened a meeting of the Muslim leaders of the subcontinent, and they unanimously agreed to relinquish the demand for a separate electorate for Muslims if the Hindus accepted what came to be known as the Delhi Proposals: four proposals that the Muslims found integral to their cooperation with the Hindu leadership. Unfortunately, the Hindu leadership would come to reject these proposals when they sat down to draft a new constitution.
In 1927 the British Simon Commission met to study the result of the Montagu-Chemsford reforms a decade after they had been put into place. The meeting was seen as a British way to avoid meaningful change, and the Muslim League split into two factions over the issue of whether or not to cooperate with the British. The Jinnah League, headed by the same Muhammad Al Jinnah who had drafted the Delhi Proposals, supported a boycott of the British while the other wing, the Shafi League, supported cooperation with the British.
In early 1928, over 100 representatives of Muslim political organizations and the Indian National Congress met to draft a constitution. Unfortunately, a consensus could not be reached, with the issue of minority rights being the main obstacle. The representatives met again one month later, in March, with the same result, and finally in May of 1928 appointed a nine person committee, headed by Motilal Nehru, to draft a constitution. Two of the nine committee members were Muslim.
After three months of work, the committee issued the Nehru Report, which called for the abolishment of separate electorates and called for the reduction of Muslim representation in the Central Assembly, as well as rejecting the previously accepted Delhi Proposals. Muslims refused to accept the report, but Congress went ahead to adopt the report, threatening the British with another noncooperation movement if the terms were not implemented soon.
The issue of the Nehru report reunited the two wings of the Muslim league, and in 1929 the All Parties Muslim Conference met to discuss Muslim demands to counter the report. It was here that Jinnah, who had previously championed Muslim and Hindu cooperation, announced his split with Hindus and the Indian National Congress.