Let’s talk about thighs. Or do I mean knees? Then let’s talk about assault – or should that be groping? Allegations against the prime minister Boris Johnson related to his conduct at a Spectator magazine lunch in 1999 have overshadowed what were meant to be a string of headline-grabbing announcements at the Conservative party conference.

Reactions to the allegations, which Johnson denies, tell us a lot about the gap between law and perception when it comes to sexual harassment and assault. It is something that the legal profession, perhaps surprisingly, can also struggle with.

Language matters here, because it is used to confuse and downgrade the seriousness of what’s alleged in common perception.

The journalist Charlotte Edwardes alleged her thigh was grasped. Yet an unattributed cabinet minister defending Johnson inserts the phrase ‘pinching a knee’. Columnist Toby Young also says ‘knee’. In fact, a lot of people who were not present and have no inside knowledge are saying ‘knee’.

Systematically changing the specifics of someone’s allegation before denying the different allegation they have just invented is a problem here, as it is intended to somehow downgrade it. But it’s not the biggest problem.

The use of the word ‘grope’ also brings in a word that could describe a situation that is consensual, or one that is not.

Does the allegation amount to one of sexual assault is a more valid question. The CPS says sexual assault is ‘when a person, male or female, touches another person sexually without their consent. Touching can be done with any part of the body or with an object’.

The standard set out by the CPS is lower than many people would think.

Catriona Watt, employment law partner at City Firm Fox & Partners, set this out when I interviewed her in February. When she conducts training on sexual harassment in law firms, she says: ‘The definition is commonly misunderstood.’ The definition, she notes, ‘is not about intention. It’s about perception’. 

Johnson, then, gets to deny this allegation. But he doesn’t get to define it - that is up to Edwardes.

One common line related to the Gazette when a complaint by an employee of harassment or assault is rejected, is a finding that carries the comment obiter, ‘we’d all had a lot to drink that night’. Again, harassment is illegal – a position not changed by too much, or indeed any, booze. To stick with the legal profession for a moment, while its members are trained to know or check the law, this seems to be a blind area for some – as Watt relates, too many just think they know the answer.

A scenario like the one Edwardes alleges falls firmly under the definition of sexual harassment under the Equalities Act 2010. That is, physical behaviour, including unwelcome sexual advances, touching and various forms of sexual assault.

The nature of what she alleges violates dignity, and if true may have had the effect of creating an intimidating, hostile, degrading, humiliating or offensive environment. Who gets to decide if actions had that effect? Against the assumptions of those spinning against people who make such allegations, the answer is: the victim.

What is more, the definition can be met without reaching a threshold where a prosecution would proceed. It can still be illegal.

Plenty of people can be found to disagree with the way the law has been framed in this area. But presumably when they also change words, and even body parts, they are hoping that an allegation’s importance will fade or that the allegation will be dropped.

But as they do so, let’s not pretend they’ve done so on any grounds that has a basis in law – even if the relevant law is widely misunderstood.