New Delhi, Mar 22 : The Congress Party has expressed regret over the alleged derogatory remarks of Shiv Sena party chief Uddhav Thackeray on Prime Minister Manmohan Singh.

According to media reports, Thackeray referred to the Prime Minister and the United Progressive Alliance in a derogatory manner while addressing a public rally in Mumbai on March 20.

Congress spokesperson Manish Tiwari has urged the Election Commission to take serious note of the incident.

Talking to the reporters here on Saturday, Tiwari said, "It''s extremely unfortunate that Shiv Sena chief has used such un-parliamentary language against the Prime Minister. It is not only an insult to that person but it is an assault on the institution also. So, therefore we do hope that the Election Commission will take serious note of it."

Meanwhile, the Mumbai city collectorate has warned an action against Thakeray under the IPC and Representation of People Act, 1923.

Mumbai city collector IZ Kundan said video recordings of the speeches delivered by all the leaders at the meet are being examined.

"The tapes are being viewed by officials, and action under the Representation of People''s Act and the Indian Penal Code, will be initiated if anything incriminating is found," she said. (ANI)