Why should a woman be paid half what a man is for the same work?
Carrie Gracie's public resignation at the weekend was an explosion in the gender wage-gap war at the BBC. Insiders at the corporation's Broadcasting House tell Charlotte Edwardes of a divided organisation and a 'corrosive' atmosphere
It's hard to imagine how Carrie Gracie, the BBC's first China editor, felt when the corporation's top salaries were published last summer and it was shown that Jon Sopel, North America editor, was paid 50% more than her.
"Livid doesn't cover it," says one colleague. "It was a kick in the teeth," says another. After all, a specific condition of taking the job in Beijing (and she'd turned it down multiple times) was the assurance that she "must be paid equally with my male peers".
Instead, she was paid £135,000 while Sopel was paid "up to £250,000". There was a similar pay discrepancy between the two other international editors: Katya Adler, Europe editor, was level-pegging with Gracie, while Middle East editor Jeremy Bowen was paid "up to £200,000". Two women versus two men - with salaries an explosion apart.
Last Sunday, after six months of "trying to resolve the situation", Gracie "cracked". Her resignation - part open letter, part hand grenade lobbed through the revolving doors of Broadcasting House - expresses her rage at the corporation's inertia in dealing with the gender pay gap.
Gracie's case highlights a corporation-wide issue: nearly 200 women in news and current affairs, from senior star journalists, to producers and editors, are in a rolling boil of complaints, or grievance procedures, over equal pay.
At least 10 have sought the advice of law firms, such as Mishcon de Reya. Morale is said by both male and female employees to be "terrible". Added to which, the BBC's long-mocked slowness to act - "It's an oil tanker, not a speedboat" - has made those in grievances feel "exhausted".
This week, pressure was piled on the BBC in parliament. On his first day as Secretary of State for Culture, Media and Sport, Matthew Hancock answered an urgent question on Gracie's resignation.
"This isn't just a matter of levelling women's pay up - it is a matter of pay equality," he said. "The BBC have begun to act and I welcome that. But more action, much more action, is needed."
As many new BBC appointments are women (in order to address the gender balance across the corporation), women appear to be given lower salaries than men who have been at the corporation for a while, say management.
But this refusal to admit that there has been any systemic gender pay discrimination makes those involved in actions enraged.
"It's institutional gas-lighting", says one employee. Another says: "This denial has had a corrosive effect on women's self-esteem. You've been told 'no' so many times that there's no inequality you think you're going mad. And so people go to lawyers to be told, 'No you're not going mad - this is happening.'"
It won't help that management describes those seeking legal advice as essentially obstructive. "It's harder to (resolve) this once everyone has fallen out with each other and gone legal," one senior management figure told me.
Nor will their seeming intransigence over explaining pay differences.
A major point in Gracie's letter is that while refusing to match her pay to her male colleagues, the BBC also refused to explain any difference between their roles that accounted for the shortfall.
So, what if the BBC is sued over equal pay? I ask senior management.
"We will say, if it goes to a legal process, that there are objective reasons why those salaries are paid differently. I would imagine Carrie would disagree with that, but that is a classic thing that gets argued the whole time in terms of equal pay.
"It's not that you have to pay people the same; it's that you have to have justification for any differences."
I put this to a female presenter who has had experience of working in both Washington and Beijing. She responds with a long sigh.
"I have reported from both and I can tell you in a split second which is easier. There is nothing easy about reporting in China. It's isolated, the language is hard, questions must be submitted by fax a month in advance, you're constantly watched, the authorities actively obstruct you."
Even male correspondents admit, "It is quite hard to argue that the Washington job is materially harder, or somehow more senior, than the China job - even if the traditional hierarchy at the BBC has dictated that politics, North America and economics are the plum jobs."
Many say the slowness of BBC bureaucracy to deal with pay discrepancies even before publishing them in July is partly to blame for the current crisis.
Since then, the approach appears to have been inconsistent; switching between strategic "sensible management" and the desperate chucking out of cash to solve problems on a case-by-case basis.
In cases such as Katya Adler's, they have offered huge uplifts in a cost-cutting climate. "Not what might be described as good for morale," says one newsroom staffer. It's been going on for "months and months," says another, who describes the human resources department as "utterly overwhelmed".
Management say they will not put up pay "overall", but "negotiate men down and get men to move on". But, they admit, "it's hard yards. It's hard yards on both sides".
"By 2020, if we can get to 50-50 with gender and people from diverse backgrounds, then that would feel like something which people would say was market-leading."
Perhaps, the source adds, "when other companies publish their gender pay it will highlight suddenly the BBC at 10% doesn't look so bad".
With lawyers boxing in management on both sides, it's hard to see beyond the impasse. Some have high hopes for a meeting between those BBC women who are leading the charge against gender inequality and the director general Sir Tony Hall next week.
Others are placing a lot on the shoulders of Fran Unsworth, who has recently taken over from James Harding (who, according to one colleague, left in part because of the "mess").
"James Harding used to say he didn't know which of the BBC levers worked: he would pull one and nothing would happen. Perhaps Fran can find the ones that work."
This week she sent the newsroom an email saying: "BBC pay equality is vital."
Well, it's a start.