A woman who worked on the Trump presidential campaign has sued the President, accusing him of kissing her without consent before a 2016 rally in Tampa, Florida. 

Alva Johnson said in the lawsuit, filed on Monday in US District Court in Florida’s Middle District, that the alleged incident was “part of a pattern of predatory and harassing behaviour towards women” by Mr Trump.

Mr Trump has denied charges by a number of women who say he groped and kissed them over a period of years without permission, and the White House was quick to dismiss the latest claim.

“This accusation is absurd on its face,” White House spokeswoman Sarah Sanders said in a statement Tuesday.

“This never happened and is directly contradicted by multiple highly credible eye witness accounts.”

The lawsuit alleges the encounter occurred inside a campaign vehicle before a rally on August 24, 2016.

While leaving a meeting in the vehicle, Mr Trump gripped Ms Johnson by the hand and leaned in so close that she felt his breath, the lawsuit says.

Ms Johnson turned her head, trying to avoid contact, but Ms Trump still managed to kiss the corner of her mouth, the lawsuit says.

Ms Johnson claims Mr Trump had to move deliberately because her face was framed by a baseball cap.

“She felt confused and humiliated,” the lawsuit said.

Ms Johnson says she felt humiliated by Mr Trump. Photo: Facebook

High-profile Trump supporters, including then-Florida Attorney General Pam Bondi and Mr Trump’s Florida campaign director Karen Giorno, were in the vehicle at the time, the lawsuit said.

Both told the Washington Post, which first reported the lawsuit, that they saw nothing inappropriate.

Ms Johnson is seeking financial damages and a court order to prohibit Mr Trump “from grabbing, kissing or otherwise assaulting or harassing women without prior express consent”.

According to the lawsuit, Ms Johnson called her partner and her parents in tears the day of the encounter with Mr Trump and described what had happened.

She said fellow campaign workers subsequently joked about the kiss after Ms Giorno shared details.

In a phone interview on Monday, Ms Johnson’s lawyer, Hassan Zavareei, rejected the White House denial and said the witness accounts were not credible.

He said Ms Johnson, 43, a mother of four living in Alabama, was not available for an interview and worries about her family’s safety as a result of the lawsuit.

The lawsuit said Ms Johnson also experienced discrimination as one of the campaign’s few female and African-American staff members.

She earned less than her colleagues and experienced “a larger culture of racist and sexist behaviour,” the lawsuit said.

-Reuters