RPN Singh was welcomed into the BJP on Tuesday.
Senior Congress leader RPN Singh who joined the BJP on Tuesday, weeks ahead of next month's key state polls, was succinct in the critique of his former party.
"I have been in a party for the last 32 years, but today I must say that that party is no longer what it used to be," he said at the news conference to announce his move.
"Today, everyone knows that if there is one party that is working for the benefit of the people and is working on Rashtra Nirman (nation's progress), It is the BJP," he added.
"This is a new beginning for me," Mr Singh, one of the Congress's most prominent leaders in Uttar Pradesh which will hold elections starting next month, said.
Speaking to journalists later, he said, "It's not the ticket-seekers who are leaving the party today. It's those people who have served the party for 25-30 years. And they have served without any motive. People have given their entire lives to Congress. And I am not talking about leaders but grassroots workers. There's almost a rush to get out. It's a sad thing."
Mr Singh is the second big exit from the Congress in Uttar Pradesh after Jitin Prasada who quit last year and was later made a minister in the Yogi Adityanath government.
The 57-year-old politician was also the in-charge of Jharkhand affairs of the Congress, where the party is in power along with the Jharkhand Mukti Morcha (JMM).
He has earlier represented the Padrauna assembly constituency and had defeated Swami Prasad Maurya from Kushinagar in the 2009 Lok Sabha polls.
Long considered a close aide of Congress leader Rahul Gandhi, Mr Singh was on Monday included in the Congress list of 30 star campaigners for the first phase of elections in Uttar Pradesh that begin February 10 with results due on March 10.