The female staffer who suffered the alleged sexual abuse told another Member of Parliament (MP), who on Monday revealed the allegations during a House of Commons debate.
Mark Garnier, an MP and under Secretary of State for International Trade, has already admitted asking his secretary to buy sex toys and to referring to her as “sugar t***”.
He is expected to lose his job after UK Prime Minister Theresa May refused to say she had confidence in him.
Leader of the House of Commons Andrea Leadsom said lawmakers risk losing their ministerial roles as a consequence of abuse allegations, even if their behavior falls significantly below “criminal activity.”
A list of 36 Conservative MPs alleged of sexual abuse and inappropiate behavior has been drawn up by staffers and leaked.
But it was in the Commons chamber on Monday that the new allegation of an assault emerged, as the growing scandal looked set to dominate the week in politics.
Last week, a BBC survey found out that half of British women and a fifth of men have been sexually harassed at work or a place of study.
Women in the US and UK have recently been coming forward to share encounters of sexual harassment and assault in the workplace, including in the media and entertainment industries and the realm of politics.
An avalanche of sexual misconduct allegations have been made in recent weeks against Hollywood producer Harvey Weinstein. The scandal has rippled in a wide range of industries.
UK police investigating Weinstein are now looking at sexual assault allegations from seven women. The incidents allegedly took place between the 1980s and 2015 both in London as well as outside of Britain.
The UK has been struggling to deal with a series of sexual abuse scandals that have raised doubts about how institutions, including the church, sports teams and the news media respond to those who are vulnerable to abuse.
A vast inquiry has been opened into child sexual abuse at a string of British institutions from parliament to the BBC, children's homes to churches.