New Delhi, Feb 8 (IANS): The Congress on Wednesday strongly criticised Prime Minister Narendra Modi over his "raincoat" barb against his predecessor Manmohan Singh and demanded an apology for it. The party said the remark was in extremely poor taste.

Congress leader Kapil Sibal said the opposition party will not allow Modi to speak in Parliament unless he apologised.

Speaking in the Rajya Sabha, Modi said only Manmohan Singh knew the art of bathing while wearing a raincoat, prompting the Congress members, including Manmohan Singh, to walk out.

"Modi chooses to speak when everyone else is done with and then makes unsubstantiated allegations. We cannot tolerate this. We will not let him speak until he apologises for his remarks," Sibal said while likening Modi's remarks to a "chieftain addressing a local crowd".

Former Union Finance Minister P. Chidambaram said the remarks were in "extremely poor taste and unbecoming of a Prime Minister".

"I have never seen a Prime Minister making such derogatory remarks about a former Prime Minister. The kind of words that he has used are unacceptable," said Congress leader Digvijaya Singh.

Congress leader Renuka Chowdhary was also scathing in her criticism.

"This is what the country is coming to that you have the Prime Minister coming to Parliament and not even giving respect to a former Prime Minister," she said.

"He can say what he wants to, we cannot stoop to that level. And that is why we walked out (of the Rajya Sabha). Our self-respect is intact, let the Prime Minister prove his," she added.

"There is a lot for us politicians to learn... so much happened but he (Manmohan) did not get a taint. Only doctor sahab (Manmohan Singh) knows the art of bathing (while) wearing a raincoat," Modi said while replying to a debate on the Motion of Thanks to the President's Address to the joint sitting of both houses of Parliament on January 31.