(Reuters) - Adult film star Stormy Daniels’ lawyer asked a federal judge for permission to question U.S. President Donald Trump under oath over an agreement to keep her quiet before the 2016 election about their alleged sexual relationship.

The White House has denied that Trump had sex with Daniels. She sued Trump on March 6 saying he had not signed a $130,000 agreement for her to stay silent, so it was invalid. Daniels, whose real name is Stephanie Clifford, and her lawyer have also said the payment was an illegal campaign contribution.

Lawyer Michael Avenatti filed a motion in U.S. District Court in Los Angeles asking the court to allow depositions of Trump and Trump’s personal lawyer Michael Cohen.

Neither lawyers for Trump and Cohen nor the White House responded to requests for comment on Wednesday about the request for depositions.

Avenatti said in the motion that he would need no more than two hours to question Trump and Cohen. A hearing is scheduled for April 30 in federal court in Los Angeles on the matter. Avenatti also is seeking an expedited jury trial.

Avenatti said the depositions and documents were necessary to resolve whether Trump was aware of any agreement, was a party to it, or ever consented to it, as well as whether he had any relationship with Daniels.

She said they had sex once in 2006 but that they kept in touch for a period of time. A former Playboy model Karen McDougal has described having a 10-month affair with Trump starting the same year, which the White House has said Trump denies. Trump was married to his wife Melania at the time.

In Avenatti’s court filing, he cited the 1997 Supreme Court case Clinton v Jones stemming from Arkansas employee Paula Jones’ sexual harassment suit against President Bill Clinton.

In that case, the high court ruled that a sitting president is not granted significant protection from civil litigation, paving the way for Clinton to be questioned about his relationship with White House intern Monica Lewinsky.

On Monday, after Daniels appeared on CBS News’ “60 Minutes” on Sunday night, Avenatti amended the lawsuit to claim that Cohen had defamed his client by suggesting she was a liar. Cohen said Daniels made defamatory statements about him in the TV interview.