Congress leader Adhir Ranjan Chowdhury wrote to President Droupadi Murmu on Friday and apologised to her for using an incorrect word while referring to her post, explaining that it was indeed a slip of the tongue.

In a letter to the President, he said that he mistakenly used an incorrect word for her and it was a slip of tongue.

"I am writing to express my regret for having mistakenly used an incorrect word to describe the position you hold. I assure you that it was a slip of the tongue.

"I apologise and request you to accept the same," Chowdhury said in his letter to the President.

While talking to reporters during their protest at Vijay chowk on Wednesday, Chowdhury had used the word 'rashtrapatni" for President Murmu, that created a row with the ruling BJP raising the issue in Parliament, demanding an apology from him and Congress President Sonia Gandhi.

A major political row broke out on Thursday over Chowdhury's 'rashtrapatni' remark with the BJP launching an all-out offensive against the opposition party, accusing Chowdhury of hurling a "deliberate sexist insult" at President Droupadi Murmu and demanding an apology from Congress chief Sonia Gandhi.

In his defence, Chowdhury, who is the leader of the Congress in Lok Sabha, had said he never intended to disrespect the President and his 'rashtrapatni' remark was a "slip of the tongue".

Accusing the BJP of making a "mountain out of a molehill" over the issue, he said he will apologise to President Murmu but not to "these pakhandis" (hypocrites).

The Congress leader said he has sought time from the President the day after tomorrow and will apologise to her if she has been offended by his inadvertent comments.

Taking on the Congress, both inside and outside Parliament, Union ministers Nirmala Sitharaman and Smriti Irani said Chowdhury used the term knowing well that it demeans Murmu and her office and is against India's values. Both houses also witnessed frequent adjournments due to protests by BJP members on the issue.

"Chowdhury's comments were not a slip of tongue. It was a deliberate sexist insult against the President," Sitharaman said, making a brief statement in Rajya Sabha.

Demanding an apology from the Congress president, the finance minister said Sonia Gandhi appointed Chowdhury as the leader in Lok Sabha to speak and he had insulted the President.

The BJP also fielded six of its tribal leaders, including three Union ministers - Kiren Rijiju, Sarbananda Sonowal and Bharati Pawar, to attack the Congress over the issue.

Addressing a press conference at BJP headquarters, the leaders said Sonia Gandhi should tender an apology to the country on behalf of her party as Chowdhury had insulted the tribal community as well as women.

Chowdhury's clarification was even "more objectionable" as he has tried to make light of the remark, Rijiju told reporters.

"What he said was not a mistake. He said it deliberately and with stress," Rijiju said, criticising the West Bengal leader for his allegation that the BJP was making a mountain out of a molehill.

Alleging that the Congress has been targeting Murmu "maliciously" ever since the BJP-led NDA named her its presidential candidate, Irani said she was called a "puppet" and a "symbol of evil" by its leaders.

"A tribal woman from a poor family who created history is being continuously demeaned by the Congress," she told reporters.

Later, a face-off between Gandhi and Irani in the Lok Sabha chamber added to the already raging row over Chowdhury's remark with the Congress accusing BJP MPs of subjecting the party chief to "brutal heckling, verbal assault and physical intimidation", and demanded an apology from Prime Minister Narendra Modi.

The incident took place after Gandhi walked across to the Treasury benches and sought to know from BJP member Rama Devi why she was dragged into the issue.

Irani stepped in and was seen gesturing towards Gandhi and apparently protesting Chowdhury's remark. Gandhi at first tried to ignore Irani's protestations, but was soon seen gesturing towards the minister and speaking angrily.

NCP member Supriya Sule and Trinamool member Aparupa Poddar were seen escorting the Congress president away from the Treasury benches as BJP members flocked around Rama Devi and Gandhi.