Brexit border talks entering critical 24 hours

Is it done?

Not yet. But, but, but, after two days where it has felt that there has been very little movement indeed, tonight, the atmosphere has changed.

Well-placed sources on the EU and UK sides sound suddenly cheerful.

New language to add to the agreement that failed to persuade the DUP at the start of the week has been discussed approvingly in London, Brussels and Dublin.

And on Thursday evening, European Commission President Jean-Claude Juncker's spokesman posted this:

But the DUP, who blocked the deal on Monday, humiliating Theresa May, are not yet fully on board.

Until their support can be guaranteed, don't expect Theresa May to get on the plane.

They are no strangers to taking their time, and making the most of their maximum moments of leverage.

It is possible that Theresa May could, by Friday evening, have been to Brussels and back, and have an agreement approved that would allow the Brexit talks to move on to the next phase.

It's also possible that this latest plan will fall foul of her Belfast allies and indeed, some figures in her own party.

A senior source told me on Thursday: "If she can't solve it in the next couple of days, how could she solve it in the next month?."

The next 24 hours are critical not just to the talks, but to Theresa May's future.