A Congress veteran switching loyalty to Mayawati's Bahujan Samaj Party may mar the grand old party's vote bank in Allahabad North assembly seat despite it roping in an independent who registered impressive showings in previous polls.

Cashing in on the rivalry between All India Women's Congress chief Rita Bahuguna Joshi and veteran leader Ashok Bajpai, the BSP is trying to expand its base in the constituency where BJP candidate Narendra Kumar Singh Gaur is seeking re-election for the fifth straight time.

Bajpai recently joined the BSP, which has given a ticket to his son Harsh Vardhan, an entrepreneur and technocrat.

The senior Bajpai had earlier won this seat.

The Bahugunas and Bajpais have been at loggerheads for a long time and the differences resurfaced recently when Rita Bahuguna Joshi, the daughter of late H N Bahuguna, reportedly was instrumental in the senior Bajpai getting a cold shoulder from the Congress leadership.

The Congress is fielding Anugrah Narain Singh in the hope that his impressive showing as an independent backed by the party's traditional vote bank would make him a front-runner in the polls to be held on May 3.

Singh, better known as a protege of former prime minister V P Singh, was reportedly wooed by the NCP recently but was soon hijacked by the Congress.

Singh had earlier won the Allahabad North seat. But the task for Congress has become difficult with the senior Bajpai, who has considerable clout among party supporters in the constituency, switching over sides and managing to get a BSP ticket for his son.

Rumours have suggested that a 'new equation' is in the offing between the family of BSP general secretary Satish Chandra Mishra, an advocate general during Mayawati's tenure as chief minister, and the Bajpai family.

The Samajwadi Party has fielded K P Srivastava, a former mayor, with an eye on Kayastha votes in this posh constituency with its adjunct of slum clusters.