Kolkata, Nov 25 (IANS): Beleagured by serial desertions from its ranks to West Bengal's ruling Trinamool Congress, the Congress Monday suffered another setback when one of its state vice presidents joined the Mamata Banerjee-led party.

Ajoy Dey, a sitting Congress legislator from Shantipur consistency of Nadia district, formally pitched his lot with the Trinamool at a media meet in the presence of its national general secretary Mukul Roy.

Dey said he was joining the Trinamool to be a partner in the "massive welfare and development initiatives undertaken by Chief Minister Mamata Banerjee".

He is the third Congress legislator in the state to cross over to the Trinamool since the 2011 assembly polls.

Earlier, Humayun Kabir of Rejinagar in Murhsidabad district and Krishnendu Narayan Chowdhury of Englishbazar in Malda district switched allegiance to the Trinamool. Both were rewarded with ministerial berths, but Kabir had to resign after he lost the by-election.

In recent months, many elected representatives in municipalities, municipal corporations and panchayat bodies have left the Congress and moved on to the Trinamool.