In 1982 assembly elections, Amin was however defeated at Titagarh by 132 votes. In the same year, he was co-opted into the Central Committee of the party. In 12th party congress at Calcutta in 1985, he was elected as a member of the Central Committee along with Anil Biswas, Biman Bose and Buddhadeb Bhattacharjee. In 1984 parliament elections, he was launched as a candidate from Barrackpore (Lok Sabha constituency). However, he lost as Indian National Congress gained sympathy votes following the assassination of Prime Minister Indira Gandhi. He lost assembly elections from Titagarh again in 1987 as Prime Minister Rajiv Gandhi declared that if Congress wins at Titagarh, he would ensure that all the closed mills & factories would be re-opened. In 1988, he was nominated as a candidate by his party into the Rajya Sabha and remained as an MP till 1994, and re-located to New Delhi.
