Donald Trump says women who accuse him of sexual assault are lying

President also accuses Democrats of wasting 'thousands of hours' over Mueller investigation

Donald Trump says attempts to have Congress investigate allegations of sexual assault against him are based on "false accusations and fabricated stories of women who I don't know and/or have never met".

In the same tweet, Mr Trump accused Democrats of "thousands of hours wasted and many millions of dollars spent" over the Mueller investigation that has been "unable to show any collusion with Russia".

The President has been accused by 16 women of sexual misconduct.

At a press conference on Monday four of them shared their first-hand experiences of Mr Trump.

Samantha Holvey, a former beauty queen who claimed the 71-year-old ogled her and other Miss USA pageant contestants in their dressing room in 2006, said his election was "heartbreaking".

"We're private citizens and for us to put ourselves out there to try and show America who this man is and how he views women, and for them to say, 'Eh, we don't care,' it hurt,” she said.

“Let's try round two. The environment's different. Let's try again.”

Another described how Mr Trump allegedly tried to kiss and put his hand up her skirt during a flight in the 1970s.

Rachel Crooks, a former Trump Tower receptionist who said the billionaire kissed her on the mouth without consent in 2006, called for Congress to “put aside party affiliations and investigate Trump's history of sexual misconduct”.

Several Democratic senators have seized the moment and called for Trump to step down.

“President Trump should resign,” New York Senator Kirsten Gillibrand told CNN on Monday. “These allegations are credible; they are numerous. I've heard these women's testimony, and many of them are heartbreaking.”

Mr Trump responded on Twitter, accusing Ms Gillibrand of "begging" for campaign contributions from him "not so long ago".

He wrote: "Lightweight Senator Kirsten Gillibrand, a total flunky for Chuck Schumer and someone who would come to my office 'begging' for campaign contributions not so long ago (and would do anything for them), is now in the ring fighting against Trump. Very disloyal to Bill & Crooked-USED!"

New Jersey Senator Cory Booker and Oregon Senator Jeff Merkley have also called on Mr Trump to resign.

The spotlight is turning back onto the President's past conduct amid the international #MeToo movement and the removal of many men from positions of power following accusations of sexual assault and harassment.

On Monday, press secretary Sarah Huckabee Sanders dismissed accusations against the Republican president and suggested the issue had already been litigated in Mr Trump's favour on Election Day.

A Capitol Hill investigation into Mr Trump's conduct appears unlikely. The Senate and House Ethics Committees investigate members of Congress, not presidents, and Republican-led committees would be loath to investigate Trump on sexual misconduct unless there is some sort of connection to the ongoing Russia probe.

Republican Senator Lindsey Graham said Congress should not investigate the allegations against Mr Trump.

“I don't think there's any forum for us to do that,” he said. “Just think about how that could be abused.”

Additional reporting by AP