Britain's Secretary of Defense Michael Fallon leaves 10 Downing Street after a cabinet meeting in London on June 27. (Stefan Wermuth/Reuters)

Britain's defense secretary Michael Fallon abruptly resigned Wednesday following allegations of inappropriate sexual behavior.

Fallon, 65, is the first British lawmaker to resign amid a growing number of claims against British politicians that have emerged in the wake of the Harvey Weinstein scandal, which has encouraged people around the world to share their stories about sexual harassment and assault.

Earlier this week, the Sun tabloid newspaper ran a front-page story about Fallon — or Sir Michael as he is known now after he was knighted in 2015 — repeatedly putting his hand on a well-known radio journalist's knee at a dinner in 2002.

The journalist, Julia Hartley-Brewer, dismissed the incident as "mildly amusing," and said, "no one was remotely upset or distressed."

But British media reported that there may be similar incidents that have occurred more recently.

In his letter of resignation, Fallon wrote, "A number of allegations have surfaced about MPs in recent days, including some about my previous conduct. Many of these have been false but I accept in the past I have fallen below the high standards that we require of the armed forces that I have the honour to represent."

He concluded, "I have reflected on my position and I am now resigning as defense secretary."

Fallon is a well-regarded defense secretary, with decades of service in a series of top government posts. He was initially opposed to Britain leaving the European Union, fearing that it would strengthen Russia's hand on the continent.

Responding to the resignation, British Prime Minister Theresa May said: "I appreciate the characteristically serious manner in which you have considered your position, and the particular example you wish to set to servicemen and women and others."

May did not mention the allegations of sexual misconduct in her letter. Instead, she thanked Fallon for his service — in four departments of state under four prime ministers — and wished him well in continuing to serve in parliament.

Before Fallon's resignation, Hartley-Brewer recalled the incident in a statement. "I calmly and politely explained to him that if he did it again I would 'punch him in the face.' He withdrew his hand and that was the end of the matter."

After Fallon apologized, Hartley-Brewer tweeted that "No one was remotely upset or distressed by it. My knees remain intact."

Hartley-Brewer told Sky News on Wednesday evening that she didn't think the resignation was due to "knee-gate" alone.

"I'm assuming that there are more allegations to come whether in a tabloid newspaper tomorrow or sooner than that," the journalist said. "I doubt very much it was a result of my knee -- and if it is, then I think that's really mad and absurd and crazy."

In the global fallout of the Weinstein scandal, clouds have been gathering over Westminster.

A number of claims have been made against British politicians in recent days.

International Trade Minister Mark Garnier is under investigation following claims that in 2010 he asked his then-secretary to buy sex toys for him and referred to her as "sugar t—."

Garnier didn't deny the claims, but said that it was "good-humored hijinks" and didn't amount to sexual harassment.

Stephen Crabb, the former work and pensions secretary, apologized for sending explicit text messages to a 19-year-old woman hoping to get a job in his office in 2013.

The Environment Secretary Michael Gove also apologized for his "clumsy" joke about Harvey Weinstein during a radio interview.

Asked his opinion of the tough questions often asked during the BBC flagship radio "Today" program, Gove replied to the host John Humphrys, "Sometimes I think that coming into the studio with you John is a bit like going into Harvey Weinstein's bedroom."

Another guest, former Labour leader Lord Kinnock said: "John goes way past groping...way past groping."

Gove later apologized "for my clumsy attempt at humor."

Another investigation is underway following claims that Damian Green, May's de facto deputy, made unwanted sexual advances towards a writer 30 years his junior. Green denied the allegations.

A so-called "dirty dossier" has been making the rounds of Westminster -- a list of 40 Conservative lawmakers accused of inappropriate behavior or unwanted sexual advances. One politician is accused of being "handsy at parties," another is dubbed "Cop-a-feel."

Some lawmakers have rebutted the allegations. A researcher whose name is on the list tweeted that "nothing of the kind implied by my name being included on this spreadsheet ever took place."

In response, May has called for a tougher system to crackdown on abuse at Parliament. She has written to the speaker of the house, John Bercow, calling for the establishment of an independent mediation service for those working in Parliament.

Britian is not the only country facing new allegations of sexual misconduct. In France, the Weinstein scandal has proven particularly resonant, with French women launching their own social media campaign to out their aggressors and marching through the streets of major cities, demanding an end to sexual assault.

The Paris prosecutor's office is currently investigating charges of rape by two different women against Tariq Ramadan, a prominent Swiss-born Muslim academic who has vehemently denied the charges.

Ramadan, who currently teaches at the University of Oxford, has taken stances on Muslims in Europe that have earned him few friends among France's intellectual elite, and this week, he appeared on the cover of the satirical newspaper Charlie Hebdo with a visibly erect penis, under the headline "the sixth pillar of Islam."

At present, Ramadan has not been suspended from his post at Oxford.

James McAuley in Paris contributed to this article.