Jinnah broke with the Congress in 1920 when the Congress leader, Mohandas Gandhi, launched a law-violating Non-Cooperation Movement against the British, which Jinnah disapproved of. Unlike most Congress leaders, Gandhi did not wear western-style clothes, did his best to use an Indian language instead of English, and was deeply rooted to Indian culture. Gandhi’s local style of leadership gained great popularity with the Indian people. Jinnah criticised Gandhi’s support of the Khilafat Movement, which he saw as an endorsement of religious zealotry. 28] By 1920, Jinnah resigned from the Congress, with a prophetic warning that Gandhi’s method of mass struggle would lead to divisions between Hindus and Muslims and within the two communities.  Becoming president of the Muslim League, Jinnah was drawn into a conflict between a pro-Congress faction and a pro-British faction. In September 1923, Jinnah was elected as Muslim member for Bombay in the new Central Legislative Assembly. He showed great gifts as a parliamentarian, organized many Indian members to work with the Swaraj Party, and continued to press demands for full responsible government.
He was so active on a wide range of subjects that in 1925 he was offered a knighthood by Lord Reading when he retired as Viceroy and Governor General. Jinnah replied: “I prefer to be plain Mr. Jinnah”.  In 1927, Jinnah entered negotiations with Muslim and Hindu leaders on the issue of a future constitution, during the struggle against the all-British Simon Commission. The League wanted separate electorates while the Nehru Report favoured joint electorates. Jinnah personally opposed separate electorates, but then drafted compromises and put forth demands that he thought would satisfy both. These became known as the 14 points of Mr.
Jinnah.  However, they were rejected by the Congress and other political parties. Jinnah’s personal life and especially his marriage suffered during this period due to his political work. Although they worked to save their marriage by travelling together to Europe when he was appointed to the Sandhurst committee, the couple separated in 1927. Jinnah was deeply saddened when Rattanbai died in 1929, after a serious illness. Also in 1929, Jinnah defended Ilm-ud-din, a carpenter who murdered a Hindu book publisher for publishing the book “Rangeela Rasool” which was alleged to be offensive towards the Prophet Muhammad.
Jinnah’s involvement in this controversy showed a greater inclination towards Islamic politics and a shift away from being an advocate for Hindu-Muslim unity.  At the Round Table Conferences in London, Jinnah was disillusioned by the breakdown of talks.  After the failure of the Round Table Conferences, Jinnah returned to London for a few years. In 1936, he returned to India to re-organize Muslim League and contest the elections held under the provisions of the Act of 1935.  Jinnah would receive personal care and support as he became more ill during this time from his sister Fatima Jinnah.
She lived and travelled with him, as well as becoming a close advisor.  She helped raise his daughter, who was educated in England and India. Jinnah later became estranged from his daughter, Dina Jinnah, after she decided to marry Parsi-born Christian businessman, Neville Wadia (even though he had faced the same issues when he married Rattanbai in 1918). Jinnah continued to correspond cordially with his daughter, but their personal relationship was strained. Dina continued to live in India with her family. Leader of the Muslim League