ANALYSIS: Jeremy Corbyn and Tom Watson square up in a battle for Labour's soul
When it eventually came, Tom Watson's assessment of Labour's travails was measured but no less devastating as a result.
"I love this party," said Labour's deputy leader. "But sometimes I no longer recognise it."
He said the party's failure to deal with anti-semitism among its members "shames" all those in it.
"We know in our hearts we have been too slow to respond to the shaming scourge of anti-semitism in our ranks," he added.
Watson's grim analysis was in response to the decision of seven of his fellow MPs to resign as Labour members and set up a new Independent Group in Parliament.
They included Luciana Berger, the Jewish MP for Liverpool Wavertree. In a fierce critique at the press conference announcing their departure, she said: "I cannot remain in a party that I have today come to the sickening conclusion is institutionally anti-Semitic."
In response, Watson demanded that Labour honestly examine where it is now and how it gets back to where it was.
He said: "The departure of our colleagues poses a test for our party. Do we respond with simple condemnation or do we try and reach out and extend beyond our comfort zone and prevent others from following?
"Throughout our history this party has been patriotic and internationalist at the same time. But is that a good description of what we are today?"
Watson vowed to spend the next few months working with Labour MPs to develop policies within the party's democratic socialist tradition.
The message from the deputy leader to Jeremy Corbyn was pretty clear; the way Labour goes about its business must change before more of their MPs follow their colleagues through the exit door.
But a briefing sent to all members of the Parliamentary Labour Party by Corbyn's office and seen by PoliticsHome completely rejects Watson's assessment.
In it, the Labour leader's office wholeheartedly reject that the party has been slow to tackle anti-semitism, insisting that general secretary Jennie Formby has taken huge strides in addressing it head-on.
The PLP briefing - which can be read below - sets out no fewer than 14 areas where, Team Corbyn insist, action has been taken to stamp out the problem.
Elsewhere, the document says it is "absolutely untrue" to claim that the leadership has dragged its heels in implementing Labour's Brexit policy by refusing to back a second referendum - as claimed by the Gang of Seven.
In his own statement responding to the departure of Berger et al, Corbyn refused to engage with any of the points they raised.
He said: "I am disappointed that these MPs have felt unable to continue to work together for the Labour policies that inspired millions at the last election and saw us increase our vote by the largest share since 1945. “Labour won people over on a programme for the many not the few – redistributing wealth and power, taking vital resources into public ownership, investing in every region and nation, and tackling climate change."
While Watson is demanding urgent change, Corbyn is calling for business as usual. Only one of them can win. The future success of the Labour Party will depend on who comes out on top.