No-notice Ofsted inspections: Who said what and when?
On Monday's Newsnight, Ofsted chief inspector Michael Wilshaw told us he had called for unannounced inspections when he first took up his post, but that the Education Secretary Michael Gove had rejected the idea because of concerns among head teachers.
Cue a furious response from the Department for Education, who said Mr Gove had never been a roadblock and Sir Michael had made a mistake.
On Tuesday I heard from Dominic Cummings, Michael Gove's former right-hand man. He believed Sir Michael had got it wrong and gave me a blow-by-blow account of events of that time - as someone whom, he said, had been "in the room for all the discussions".
Now, many inside government and outside see Mr Cummings as a troublemaker - at times pursuing dissent for his own ends.
But his version of events appears to chime with what the Department for Education is claiming.
He also mentions Henry de Zoete - Michael Gove's special adviser at the time - as another person present in the room then.
Mr de Zoete has confirmed this pattern of events to me:
He pursued it again in government on 4 April 2011.
This was not because of any extremism problem, but because of a wider recognition that with advanced notice inspections, schools had time to get their behavioural problems sorted, and "bussed off the troublesome kids to the beach".
Sir Michael took up his post at the beginning of 2012 and agreed on the need for change.
But by April of that year, after three or so months in the job, Sir Michael, according to Mr Cummings, had lost his nerve.
He told Mr Gove that after a series of tricky encounters with the media and what Mr Cummings refers to as "car crash interviews", he didn't feel able to announce the no-notice inspections that month.
Mr Cummings remembers a conversation between Mr Gove, himself and Mr de Zoete, in which they were informed on the change of position, and they tried to talk the education secretary back into it, saying that Sir Michael was in an over-emotional state - not one in which big decisions should be made.
But Mr Gove stuck by Sir Michael's wishes, saying, I was told, he was new to the job and needed the department's support.
The mistake, according to Dominic Cummings, came a few weeks later, on 5 May 2012.
Michael Gove attended the National Association of Head Teachers annual conference in Harrogate, and told delegates: "The perception is Ofsted has become an arm of the Spanish Inquisition… particular concern that people fear it [no-notice inspection] sends a message that we don't trust the profession."
His language was incendiary - he went further than he meant to. It was seen as a climb down, a U-turn.
Worse, it gave the impression the decision had been taken by the Department for Education and not an independently minded Ofsted.
When a furious Sir Michael confirmed the decision a few weeks later, it was assumed by many Michael Gove had led the way.
Subsequently, Number 10 feared re-opening the debate, despite much public support for the no-notice inspection approach.
They worried, I'm told, that Michael Gove was antagonising teachers too much, and not taking them with him.
Mr Gove and his team have been itching to get to the place he announced on Monday for more than two years.
And what of Ofsted?
On Tuesday, it stuck bullishly to its side of the story, insisting it had always been in favour of no-notice inspections, and that Michael Gove had been the road block to its implementation.
By mid-afternoon, a press release from the Department for Education had emerged stating the chief inspector "confirmed that the Education Secretary did not ask Ofsted to halt its plans for no-notice inspections in 2012".
When I pressed Ofsted to understand if it was true, I was told it had agreed to the statement because it thought it was "pathetic to get into a tit-for-tat argument on something they were all now agreed on".
Is it backing down on claims Sir Michael made on Newsnight on Monday? It is not.
Over to you, to decide who's telling the truth.