Twitter on Friday laid out its plan for banning political ads just as campaigns for the 2020 presidential election heat up, and for banning ads that advocate for a certain outcome on social and political causes.

Twitter said last month that it would ban political advertising, as social media companies have faced growing calls to stop accepting ads that spread false information and could sway elections.

Twitter said it will define political content under its policy as anything that references “a candidate, political party, elected or appointed government official, election, referendum, ballot measure, legislation, regulation, directive, or judicial outcome.”

“We believe political message reach should be earned, not bought,” Twitter Chief Executive Jack Dorsey said in announcing the ban.

Rival Facebook, saying it did not want to stifle political speech, has steadfastly refused calls from some politicians and others to follow Twitter’s lead, and said it would not vet political ads for misleading claims on its site.

The ban, which is expected to take effect on Nov. 22 and includes ads from political candidates, political parties or government officials themselves, was initially derided by U.S. President Donald Trump’s reelection campaign.

Twitter will allow companies and advocacy groups to run ads that promote awareness and discussion about social causes, such as environmental protection. But they will not be allowed to push for a certain political or legislative change on the issue, especially if they are advocating for something that benefits their business, Del Harvey, vice president of trust and safety, said in a conference call on Friday.

Advertisers who wish to run ads that promote awareness about a cause will be able to target users at the state level or higher, but not by their zip-code. And those advertisers will not be able to target people based on their political leanings, Twitter said.

Twitter said it will use a combination of automated technology and human teams to enforce the new ad policies.

News publishers that meet certain criteria will continue to be able to run ads on Twitter that reference political content, but they cannot advocate for or against a political topic.