ANALYSIS Has the Heathrow row finally killed off Boris Johnson's dreams of No10?
It's obvious, but sometimes it needs repeating. The first requisite for leadership is the ability to lead.
By that measure, Boris Johnson's hopes of one day entering 10 Downing Street are this afternoon receding at an alarming rate.
The sight of the Foreign Secretary trying to find a country far enough away from Britain to justify not being in the Commons to take part in a 10pm vote on a third runway at Heathrow was the antithesis of political courage.
As one Cabinet minister said: "It couldn't be more contrived."
This is the same Boris Johnson, let us not forget, who once threatened to "lie down in front of the bulldozers" to prevent Heathrow expansion from taking place. Now, he can't even bring himself to troop through the division lobby to vote against it.
The damage being done to Johnson's reputation among his Tory colleagues - those who will decide whether or not he makes it onto the leadership ballot paper at some point in the future - is career-threatening.
Greg Hands, whose resignation as trade minister in order to oppose the third runway was described as "a hospital pass for Boris", didn't think twice before mocking the Foreign Secretary on Twitter.
Justine Greening, Johnson's former Cabinet colleague, happily joined in the Conservative social media pile-on.
Sarah Wollaston, the Tory chair of the Health Select Committee, could not disguise her disdain for the MP for Uxbridge when quizzed about Heathrow on the Westminster Hour.
She said: "I think this would be an opportunity for a colleague like Boris Johnson to actually put his money where his mouth is."
And while she said no voters would realistically expect him to make good on his promise to prostrate himself in front of the diggers, "they might expect him to use this as an opportunity and to resign on a point of principle". Fat chance.
Asked if the furore was damaging for Johnson's leadership hopes, one minister told PoliticsHome that "Greg Hands effectively killed it" last week.
It is still too early to write off Boris Johnson entirely. If politics has taught us anything in the last couple of years, it is to expect the unexpected.
But there is no doubt that shares in the Foreign Secretary are currently being sold off in SW1, and he desperately needs to change the narrative before his leadership hopes are officially bust.