Facebook has received similar letters recently from the Congress as well as BJP.
Facebook has received the third letter in two weeks accusing it of political bias. In a letter to CEO Mark Zuckerberg, the Trinamool Congress has said that accounts and posts were blocked by the social media giant and pointed at a "link" between Facebook and the BJP ahead of elections in West Bengal next year.
The Trinamool Congress, which rules Bengal, claimed there was enough evidence in the public domain to substantiate its charge.
Facebook has received similar letters recently from the Congress as well as BJP. Today, Facebook officials are to appear before a panel of MPs led by Congress's Shashi Tharoor to answer questions on alleged political bias based on US media reports.
Trinamool MP Derek O'Brien, who has written to Facebook, refers to an earlier meeting when he had reportedly flagged these concerns.
"We, the All India Trinamool Congress (AITC), India's second-largest opposition party, have had serious concerns about Facebook's role during the 2014 and 2019 general elections in India," Mr O'Brien wrote in the letter, according to PTI. "With the elections in the Indian state of West Bengal just months away, your company's recent blocking of Facebook pages and accounts in Bengal also points to the link between Facebook and the BJP. There is enough material now in the public domain, including internal memos of senior Facebook management, to substantiate the bias," he wrote.
In another letter to Facebook on August 31, Mr O'Brien flagged "the removal of hundreds of Trinamool Congress supporters' pages and accounts on both Facebook and WhatsApp for community standard violations." He said numerous Facebook and WhatsApp accounts were banned in the run-up to the foundation day of his party's youth wing on August 28.
Yesterday, Union Minister Ravi Shankar Prasad, in a letter to Mark Zuckerberg, alleged that employees of the social media giant "are on record abusing Prime Minister Narendra Modi and senior cabinet ministers".
There have been "multiple instances recently where Facebook has been used by anarchic and radical elements whose sole aim is to destroy social order, recruit people and assemble them for violence. However, we are yet to see any meaningful action against such elements. Is this action also held back by the same vested interest groups who have an incentive in stoking political violence and instability in India?" - Mr Prasad wrote.
The IT minister also alleged he had been told that in the run-up to the 2019 election, "there was a concerted effort by the Facebook India management to not just delete pages or substantially reduce their reach but also offer no recourse or right of appeal to affected people who are supportive of the right-of-centre ideology".
Mr Prasad's letter emerged after the Congress wrote to Facebook on US media reports suggesting Facebook's bias while dealing with posts from members of the BJP and the rightwing. A report published in the Wall Street Journal said the social networking site did not apply hate speech rules on members of the ruling party. In a second report, WSJ alleged that Ankhi Das, head of public policy in Facebook India, "made internal postings over several years" detailing her support for the ruling BJP and disparaging its main rival Congress.