Trump deemed 'not above the law' and faces a legal storm

US President Donald Trump faced legal challenges from women on two fronts on Tuesday as a defamation lawsuit brought by a former Apprentice TV show contestant moved forward and a former Playboy model who said she had an affair with Trump sued to undo a confidentiality agreement.

The developments increased legal pressure on Trump, who during and after the 2016 presidential campaign was accused of sexual misconduct by more than a dozen women, allegations he denied.

A New York state judge on Tuesday denied a bid by Trump to toss a defamation lawsuit by Summer Zervos, a former contestant on NBC's The Apprentice, raising the prospect that he might have to answer questions about his behaviour in court.

Justice Jennifer Schecter in Manhattan rejected Trump's claim that he was immune from being sued, finding "absolutely no authority" to dismiss litigation related "purely to unofficial conduct" solely because he occupied the White House.

"No one is above the law," the judge wrote in her ruling.

Playboy model Karen McDougal sued a media company that she said paid her $150,000 to keep quiet about an affair that she said she had with Trump.

The lawsuit was the second time this month that a woman challenged legal arrangements to prevent discussions about affairs women said they had with Trump. Both involved payments that legal experts have said could equate to in-kind contributions to Trump's campaign in violation of federal election laws.

A storm brews

On another front, porn actress Stormy Daniels and her lawyer continued their media campaign against Trump as she seeks to invalidate a non-disclosure agreement she signed days before the 2016 presidential election so she could discuss their relationship.

"People DO care that he lied about it, had me bullied, broke laws to cover it up, etc.," Daniels tweeted.

The White House did not immediately respond to a request for comment.

Trump has denied all accusations of misconduct, and called his accusers "liars."

Summer fights back

Zervos met Trump when she became a contestant on The Apprentice in 2005. She said Trump kissed her against her will at a 2007 meeting in his New York office, and later groped her in a Beverly Hills hotel at a meeting about a possible job.

Zervos said Trump's denials amounted to defamation and that being branded a "liar" caused diners to stay away from her restaurant in California.

John Diamond, a professor at the University of California Hastings College of the Law, said Trump would have to testify under oath if he had to defend himself.

McDougal filed her lawsuit in Los Angeles Superior Court against American Media Inc, publisher of the National Enquirer, whose head, David Pecker, has described Trump as a "personal friend."

McDougal said American Media paid her $150,000 in 2016 for the rights to her story that she had an affair with Trump in 2006 and 2007 and then never published it.

McDougal said her lawyer at the time, Keith Davidson, secretly negotiated with Michael Cohen, Trump's personal lawyer, and that Cohen was in consultations with American Media on the agreement. Cohen has acknowledged arranging to pay to silence Daniels. That payment was also made during the election campaign.

Davidson said on Tuesday that he never had contact with Cohen during the McDougal negotiations.

"False allegations have been levied against me and I look forward to responding to them in an appropriate forum."