After her mother Rubi Noor (the then incumbent Member of Legislative Assembly of West Bengal for Sujapur constituency) died in 2008 Mausam entered politics.

Her mother, Rubi Noor, was elected to the West Bengal Legislative Assembly for three consecutive terms from the Sujapur constituency.

Her other uncle, Abu Hasem Khan Choudhury, is serving as a Member of Parliament for the Maldaha Dakshin constituency.

[7] Abu Hasem's son, Isha Khan Choudhury, is a member of the West Bengal Legislative Assembly and represents the Sujapur constituency.

[10] She worked at the legal firm Fox and Mandal and practised as a full-time lawyer in the Supreme Court of India for two years before entering politics.

Subsequently, the Indian National Congress party announced that Mausam would contest for the upcoming by-election from the constituency.

[4] She won the election and defeated her nearest rival, Haji Ketabuddin of the Communist Party of India (Marxist) by a margin of 21,205 votes.

[18][19] In December 2013, she succeeded her uncle Abu Hasem Khan Choudhury as the party president for the Malda district.

[20] During Noor's first term as an MP, 1,500 kilometres (930 mi) of road was built in her constituency under the Pradhan Mantri Gram Sadak Yojana.

[30] On 30 January, she organized a rally at Malda in which had fourteen panchayat members and one councillor of English Bazaar switch to Trinamool.

[31][32] In the election, Noor lost to Khagen Murmu of Bharatiya Janata Party, her nearest rival by a margin of 84,288 votes.

However, the Pradesh Congress chief Somen Mitra rejected the proposal as they were keen to form an alliance with the Communist Party.