"I regret for raising slogan during recital of the national anthem. It has been done out of emotion in the Mahanadi and Polavaram issues," Ray said in a statement in the Assembly after being criticised by different quarters, including his own party.
Stating that his conduct was not intended to disrespect the national anthem, Ray claimed he has maximum respect for the anthem.
Earlier, ruling BJD spokesman Samir Ranjan Dash had tendered apology outside the Assembly for Ray's conduct.
While members of the House including Chief Minister Naveen Patnaik and Speaker Niranjan Pujari were standing in respect to the national anthem, Ray was yesterday found shouting slogan opposing Chhattisgarh government's construction of projects on upstream of river Mahanadi.
"Though Patnaik was present in the House, he did not ask his party member to shun from shouting slogan during recital of the national anthem," Mishra said.