Congress MLA Kuldeep Bishnoi resigned from the Haryana Assembly Wednesday, a day before he joins the ruling Bharatiya Janata Party.
Bishnoi submitted his resignation to Assembly Speaker Gian Chand Gupta here.
His resignation will necessitate a bypoll from Adampur seat in Hisar district, which Bishnoi currently represents.
Bishnoi, 53, was expelled from all party positions by the Congress soon after he cross-voted in the Rajya Sabha polls in June.
The four-time MLA and two-time MP had been sulking since before that and had raised a banner of revolt after the party ignored him for the post of its Haryana unit chief during a revamp earlier this year.
For the younger son of former Haryana chief minister Bhajan Lal, it will be the second parting with the Congress, nearly six years after he had returned to the fold.