Gordon Brown was fully aware he would have to step down as Labour leader over recent days, confidants say.
This is noteworthy because he is frequently accused of being "delusional" and a "control freak". Instead, he recognised that his position had been damaged by Nick Clegg's ushering in of the concept of a "mandate" during the campaign, and -- remarkably -- he told Clegg face to face that he would go.
It is not clear at this stage whether the "progressive alliance", which his act of sacrifice brings to the table, will work. According to one back-channel intermediary in favour of a Labour-Lib Dem coalition, there is a danger that "the Lib Dems may get impatient, including with any early positioning for the leadership, and decide the only way forward is with the Tories".
Brown and his negotiating team will be hoping that the Lib Dems can hold their nerve against the mighty forces of conservatism that now include hostile Tories as well as the Murdoch press, a BBC acting as if it has been robbed of its script, and elements of the City. Still, the fight is on.