"BJP MP Shatrugna Sinha ji met our Congress President Shri @RahulGandhi today and in national interest has decided to join our Congress. He wil formally join Congress on April 6," he said in a tweet.
This comes after the BJP replaced Sinha, who has been critical of the party's top leadership on several occasions in the past, with its senior leader and Union Minister Ravi Shankar Prasad from the prestigious Patna Sahib Parliamentary constituency in Bihar.
The actor-turned-politician has been critical of the style of functioning of Prime Minister Narendra Modi and BJP chief Amit Shah and accused them of running the country like an autocracy.
He also slammed the BJP for denying ticket to party veterans L.K. Advani and Murli Manohar Joshi "without their consent".
Speculation has gained ground that Sinha, serving his second consecutive term, will contest the upcoming Lok Sabha elections from Patna Sahib on a Congress ticket. The BJP is contesting from 17 of the 40 Lok Sabha seats in Bihar as part of the NDA. In the opposition's 'Mahagathbandhan', the Congress is fighting on nine seats.
Earlier on Tuesday, Sinha showered praise on Congress chief Rahul Gandhi, calling him the "master of situation" and his proposed minimum income guarantee scheme--'NYAY'a "masterstroke".
He also slammed the BJP for doubting the feasibility of the proposed scheme. and drew a phrase from a yesteryear chartbuster years to make his point 'ap kare to raasleela baki kare to character dheela'.
Sinha has adopted a belligerent approach towards the BJP criticising it over a range of issues since the 2015 Bihar Assembly election. According to sources, he also played a major role in bringing the parties of the 'Mahagathbandhan' together after there appeared a disagreement among them on the issue of seat-sharing.
Earlier in the month, Sinha had said he will not change his constituency in the coming Lok Sabha election "whatever the situation", making clear he would contest again from his seat irrespective of the party decision.
"Situation kuch bhi ho, location wahi hogi (Whatever the situation, location would be same)," Sinha said.
He has often taken a stance at variance with the official party line, including on demonetisation and Goods and Services Tax, and shared the stage with opposition leaders at an anti-BJP rally in Kolkata in January, where he was projected as the "star speaker".