San Francisco CNN Business  — 

Facebook’s policies on political ads are being criticized yet again, with several civil rights leaders recently invited to CEO Mark Zuckerberg’s home slamming what they say is a “lackluster response” to their concerns.

Civil rights groups that participated in last month’s dinner meeting with Zuckerberg — including The Leadership Conference on Civil and Human Rights, NAACP and Muslim Advocates — said Wednesday that Facebook (FB) had not adequately addressed concerns about hate speech raised at the dinner.

“Our communities are being targeted by bad actors on Facebook and the company has a moral obligation to fix this ongoing problem,” the groups said in a statement emailed to CNN Business. “Facebook’s lackluster response to our serious concerns is devoid of any commitments to implement substantive measures and changes to its policies,” they added.

At the dinner, which took place on November 4, the civil rights groups raised concerns about Facebook’s policy of allowing politicians to run false ads, as well as the company’s tackling of hate speech. The groups subsequently sent a letter following up on the issues discussed at the dinner, to which Facebook responded earlier this week.

“We presume a public interest value in people hearing from and responding to politicians, but the speech is still evaluated against the risk of harm,” said the letter from Lindsay Elin, a senior Facebook public policy executive. Posts from politicians may be exempt from Facebook’s community standards if the company deems them “newsworthy,” but “all ads, including those posted by politicians, must still comply with our Community Standards and our Advertising Policies,” Elin added.

However, Facebook pushed back against one of the groups’ key demands — to subject political ads to independent fact-checking.

“We will not be sending politicians’ content to our third-party fact checking partners,” Elin said. “We have internally deliberated and discussed this issue at length and continue to believe that Facebook should not intervene in political debates or decide what information constituents can see.”

The letter also outlined other steps that Facebook has taken or is planning to take, including providing more information about advertisements, strengthening its commitment to civil rights and cracking down on voter suppression ahead of the 2020 election.

A Facebook spokesperson declined to comment beyond Elin’s letter, which was shared by the civil rights groups and addressed to Vanita Gupta, CEO of the Leadership Conference on Civil and Human Rights.

Facebook has come under fire from some Democratic presidential candidates, the US Congress, and even some of its own employees for its political ad policy, including allowing politicians to run targeted false ads. Twitter (TWTR) CEO Jack Dorsey announced last month that his platform would no longer accept political ads.

While the civil rights groups acknowledged that Facebook’s latest civil rights audit is yet to be completed, they said the company “appears to be unwilling to police its platform and enact sufficient measures on its own to protect our democracy and vulnerable communities.”

“Unless meaningful change happens, Facebook must be held to account by outside forces and measures, including legislation, regulation, strong enforcement, and litigation,” the groups added.