PM will criss-cross a nation in which she faces huge challenges

In each place, she faces huge political challenges.

England voted narrowly for Brexit, but the country is deeply divided between places such as London, which was heavily pro Remain, and Sunderland, which voted strongly for Leave.

In Parliament, influential voices are trying to overcome the 2016 referendum, or negate its effect.

Wales also voted narrowly for Brexit, but it has a devolved government that is resolutely opposed to departure from the European Union, and is making common cause with the devolved administration in Edinburgh.

Scotland was the country that voted most heavily for Remain, at 62% support, and it is resisting Brexit heavily, making coming cause with Cardiff over the return of some powers from Brussels to London rather than the regional parliaments.

In Scotland, the prime minister also faces difficulties with her own Tory MPs, most of whom opposed Brexit in the first instance, and are now annoyed about fishing rights.

In Northern Ireland, a majority of those who voted in 2016 backed Remain. Nationalists in particular are so angry about Brexit that many of them are no longer relaxed about staying in the UK in the way that they once were.

Meanwhile, the border is a massive political and legal and logistical challenge, if Northern Ireland is to leave both the customs union and single market (which Mrs May says it will, along with the rest of the UK).

None of these challenges across the kingdom are even close to being resolved, yet Brexit comes into effect one year from now. The Article 50 two-year process for exiting the EU is clearly hopelessly inadequate for such a huge undertaking.

But the prime minister has stayed in power much longer than was anticipated after last year’s election result. Today she has a chance to reassure people all over the nation that she is up to the job and its massive demands.