Krishnendu Narayan Chowdhury and Humayun Kabir, both of whom resigned as legislators on Tuesday, were drafted into the Trinamool Congress ministry, in what is being seen as Ms Banerjee's efforts to weaken her former alliance partner in its strongholds in the state.
Mr Chowdhury, who was made a Cabinet minister, had won the last election from Englishbazar in Malda district, while Kabir, sworn in as a minister of state, represented Rezinagar in Murshidabad district.
Malda and Murshidabad are considered strongest forts of the Congress in the state where the party has been steadily losing space to the Trinamool over the years.
Malda was once a pocket borough of late Railway minister Barkat Ghani Khan Chowdhury, and the strong Congress organisation there is now controlled by his family members.
The writ of Ms Banerjee's bete noire and Union Minister of State for Railways Adhir Chowdhury runs in Murshidabad.
Kabir's inclusion is considered a big blow to Adhir Chowdhury, as the new minister has for long been his protege.
Governor MK Narayanan administered the oath of office and secrecy to the two new Cabinet ministers - Krishnendu and Rajib Banerjee - at a solemn function in the Raj Bhawan in the presence of Chief Minister Mamata Banerjee, several members of her Cabinet, members of the diplomatic corps and some industrial chamber representatives.
Five Ministers of State were promoted to the Cabinet rank, and another to the Minister of State (Independent charge) status.
One new Minister of State (Independent charge) and five ministers of state were sworn in at the function, taking the strength of the Ms Banerjee's ministry to 44.
Peasant leader Becharam Manna, who emerged as the grassroot level face of the Mamata Banerjee-led movement against the construction of Tata Motors Nano small car plant in Hooghly district's Singur during the last leg of the Left Front rule, was also sworn in as a minister of state.
The anti-land acquisition movements in Singur and Nandigram in East Midnapore district played a big part in Trinamool's victory in last year's assembly polls, ending the Left Front's 34-year uninterrupted rule in the state.