Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.

Passage: While studying law and philosophy in England and Germany, Iqbal became a member of the London branch of the All India Muslim League. He came back to Lahore in 1908. While dividing his time between law practice and philosophical poetry, Iqbal had remained active in the Muslim League. He did not support Indian involvement in World War I and remained in close touch with Muslim political leaders such as Muhammad Ali Johar and Muhammad Ali Jinnah. He was a critic of the mainstream Indian nationalist and secularist Indian National Congress. Iqbal's seven English lectures were published by Oxford University press in 1934 in a book titled The Reconstruction of Religious Thought in Islam. These lectures dwell on the role of Islam as a religion as well as a political and legal philosophy in the modern age. Question: Who was Iqbal a critic of?
mainstream Indian nationalist and secularist Indian National Congress