There is now a clear split between Theresa May and her Brexit secretary Dominic Raab.
She offered a transition extension as a practical measure so that the EU’s version of the Northern Irish backstop would never have to be implemented.
But she knows the EU will not countenance a Brexit deal unless their version of the backstop is written into the Withdrawal Agreement, as an insurance or guarantee that the border between Northern Ireland and the Republic of Ireland will be kept open whatever else happens.
Raab, in the Telegraph, says an extension of the transition period is dependent on the EU abandoning its backstop - which May knows will not happen.
This policy and ideology difference - between a transition extension as a buffer to ward off implementation of the backstop or as a chip to negotiate away the backstop - is everything.
I can’t see this dispute ending well for Raab or May.
And a no-deal Brexit looks more and more likely.
If May sanctioned Raab’s statement that an extension to the UK staying as a non-voting member of the EU for an extra 12 months would be alternative to the NI-only backstop, then progress made at the EU council last week would be wiped out and no-deal Brexit would be odds on.
She knows that.