Theresa May goes public with time limit on premiership

It's official. Theresa May has just confirmed publicly what she told her MPs last night - she will step down before the next general election.

Not surprisingly she had no desire to get drawn into a conversation about a date of departure, telling us that her focus was getting an improved Brexit agreement and getting the deal "over the line".

But despite obvious demands at home from her MPs to change tack in the negotiations, No 10 seems to have little expectation of anything happening fast here, warning against an "immediate breakthrough".

But few in her party at home believe she has a genuine chance of getting a fundamentally different version of the deal - at least not at this summit.

• May asking for EU 'backstop assurances'

• How long can May survive as PM?

And minds are starting to focus on who, or what, might work instead.

The prime minister's admission that she'll leave office before the next election fended off yesterday's clamour from a chunk of her party to go.

But it hardly makes things easier from today onwards.

Just as she is desperate to get a time limit on the controversial "backstop", she now has a limit on her time in office.

Now it is public, in her own words, questions won't just be about her impossible Brexit agreement but also about how, and when, she will finally go.

As we discussed here earlier, it's one thing for prime ministers to tell their colleagues in private that they will get out of the way, as part of some kind of political trade. To say it in public is an entirely different event - a message to the public that can't be taken back.

PS: Don't all shout at once - of course, this is the same prime minister who said, time and time again, that she would not have a snap election and then, lo, and behold, she changed her mind completely. She seemed powerful then though - she and the rest of Westminster is living in a different reality now, although... never, say never.