Giving a boost to the Congress in Uttar Pradesh, and especially in Amethi, former Union minister Sanjay Singh joined the party on Wednesday.
Singh, who had joined the Bharatiya Janata Party a few years back, had unsuccessfully contested against Congress president Sonia Gandhi in the 1999 Lok Sabha election from Amethi.
He used to be a close associate of Sonia's husband and former prime minister Rajiv Gandhi.
He later parted with the Congress and aligned with the Janata Dal during the V P Singh regime.
