New Delhi, Dec 10 (ANI): Political leaders on Wednesday slammed TMC leader Kalyan Banerjee for his 'unparliamentary remarks' for Prime Minister Narendra Modi and Former Prime Minister Lal Bahadur Shashtri. The political parties are up in arms against the use of derogatory language for any leader. The Bharatiya Janata Party on Tuesday threatened to bring censure resolution against Banerjee if he does not apologise for objectionable remarks. Banerjee while addressing a public gathering in West Bengal had attacked BJP leader Siddharth Nath Singh, grandson of Shastri, and used offensive language. Politicos said that government should take strict action in the matter and not allow to leaders to go away with such remarks.