Trump has denied having an affair with Daniels.
Daniels, whose real name is Stephanie Clifford, filed the lawsuit in Los Angeles claiming the agreement is invalid and she is free to publicly discuss her relationship with Trump.
The lawsuit, which Clifford's attorney Michael Avenatti published in a tweet, says that she signed both the agreement and a side letter using her stage name on October 28, 2016, days before the 2016 US presidential election.
Trump's attorney Michael Cohen signed the document the same day, but Trump never signed the document, the lawsuit claims.
The "hush agreement" as it is called in the lawsuit refers to Trump as David Dennison and Clifford as Peggy Peterson. The side letter agreement reveals the true identities of the parties as Clifford and Trump, according to the lawsuit.
Clifford asks in the lawsuit for the Los Angeles County Superior Court to declare the agreement and side agreement invalid and unenforceable.
The White House did not immediately respond to a request for comment. Avenatti was not immediately available for comment.
Daniels was quoted in a 2011 interview with In Touch Weekly magazine that she had an affair with Trump after they met at a Lake Tahoe golf tournament in 2006, not long after Trump's wife, Melania, had given birth to their son, Barron.
Cohen has said he paid Clifford $130,000 of his own money in 2016, the year Trump was elected president, but said neither the Trump Organization nor Trump's campaign was a party to the transaction, though he declined to say publicly what it was for.
The lawsuit said the 2016 hush agreement called for $130,000 to be paid into the trust account of Clifford's then-attorney. In return, Clifford was not to disclose any confidential information about Trump.
The suit alleges Cohen has tried to keep Clifford from talking about the relationship as recently as Feb. 27, 2018.
"The attempts to intimidate Ms. Clifford into silence and 'shut her up' in order to 'protect Mr. Trump' continue unabated," the lawsuit said.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
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