New Delhi, May 14:  Former prime minister Manmohan Singh and other senior Congress leaders have written to President Ram Nath Kovind, asking him to caution Prime Minister Narendra Modi against using "unwarranted, threatening and intimidating" language to attack them.

Citing the Karnataka poll campaign, they said the "threat" given out by Modi to leaders of the party needs to be condemned as it does not behove the prime minister of a "constitutionally governed democratic country of 1.3 billion people".

The letter has been signed by Manmohan Singh as well as senior Congress leaders A K Antony, Ghulam Nabi Azad, Ahmed Patel, P Chidambaram, Ashok Gehlot, Mallikarjun Kharge, Karan Singh, Ambika Soni, Kamal Nath, Anand Sharma, Motilal Vora, Digvijay Singh and Mukul Wasnik.

The Congress leaders referred to Modi's speech on May 6 at Hubli in Karnataka in which he is quoted as saying, "Congress ke neta kaan kholkar sun lijiye, agar seemaon ko paar karoge, to yeh Modi hai, lene ke dene pad jayenge (Congress leaders should clearly hear out, if you cross limits, then this is Modi and you will have to pay a price)".

The letter has also given a YouTube link to the speech. "The President may caution the Prime Minister from using such unwarranted, threatening and intimidating language against leaders of the Congress Party or any other party or person as it does not behove the position of the Prime Minister," it said.

The prime minister, it stated, is not expected to use menacing language even in the course of an election campaign. This is tantamount to a prime minister using his powers and privileges to "settle personal and political scores", the letter said. Referring to the oath of office, it said the prime minister of India holds a very special position under the Constitution.

The Congress leaders said all prime ministers of India in the past have maintained immense dignity and decorum in the discharge of a public or private functions/actions.

"The threat held out by the Prime Minister to the INC's leadership deserves to be condemned. This cannot be the language of the Prime Minister of a constitutionally governed democratic country of 1.3 Billion people.

"Such discourse whether in public or private is unacceptable conduct. The words used are menacing and intimidating with intent to insult and provoke breach of the peace," the Congress leaders added.

They said the Congress is the oldest party in India and has faced many challenges and threats, even as its leadership has exhibited courage and fearlessness in facing them.

"We would like to state that neither the party nor our leaders will be cowed down by such threats," they said. According to the letter, the president of India is the constitutional head of the Union of India and enjoys high duty and obligation to advise and guide the prime minister and his cabinet.