Gordon Brown's leadership credentials will be under scrutiny as never before this morning when he addresses a British Labour Party conference for what he hopes will be his last time as Tony Blair's chancellor.
Damaged by accusations of disloyalty to the prime minister, Mr Brown has the tricky task of signalling both "continuity" and "change" to Labour delegates - while not seeming to take the succession for granted and at the same time persuading Blair ultras that a Brown leadership would be inclusive and unifying.
The relentless media focus on the man still most likely to succeed Mr Blair continued last night with a BBC Panorama programme asking "Has it got to be Gordon?"
And speculation as to who else might think to win the Labour crown continued apace around the G-Mex conference centre after Mr Blair again refused to endorse Mr Brown as his successor.
Plainly still wounded by the failed attempt to force him from Downing Street just weeks ago, Mr Blair said his party had gone "AWOL from the British public" at that point and that the public were "angry" about it.
Refusing to comment on newspaper reports that he would refuse Mr Brown his backing in the leadership contest, Mr Blair insisted he would spend this week "talking to the public" about their concerns about migration, terrorism and law and order.
Cabinet ministers Margaret Beckett and John Hutton breached the cabinet's promised vow of silence on the leadership issue as conference got underway - Ms Beckett in effect to endorse Mr Brown, Mr Hutton to call for a contest.
But while Blair loyalists continue the search for a credible challenger, the suspicion is growing that a "conflicted" Mr Blair is resigned to the likelihood that his once close friend - turned greatest rival, Mr Brown, may be unstoppable.
However, a second opinion poll in three days yesterday brought the worrying news for the Brown camp that while two-thirds of voters now think Mr Blair should set a clear timetable for his departure, 48 per cent to 26 per cent believe Mr Brown has not yet shown his fitness to be prime minister.