The news, broken yesterday afternoon by James Forsyth, that Stephen Parkinson, Theresa May’s senior Special Adviser, is off to work for the Vote Leave campaign is a major boost the anti-EU machine.

Parkinson is a serious operator – not only has he played a crucial role in helping his boss become the longest-serving Home Secretary since Butler in the early 1960s, he also proved invaluable working alongside Matthew Elliott in winning the referendum on AV. That he feels the Leave campaign is something to which he can happily put his name is a sign of confidence in the cause, and the hard-nosed nous he brings with him will advance it still further.

That isn’t the limit of the story, of course. Paul, writing on this site last week, was the first to mull the opportunities which a timely anti-EU declaration might offer to May. Now her closest adviser has joined Vote Leave; the Westminster mill often grinds rumours out of much less grist than this. (Incidentally, fans of political fiction will have noted that in Andrew Marr’s novel Head of State the Out camp is led by the flinty Olivia Kite, a former Home Secretary.)

The Home Secretary has long argued that freedom of movement rules should be a priority target for the EU renegotiation – not only is she personally committed on the issue, she surely knows that the repeated failure to hit the Government’s stated migration target threatens her reputation as a minister. With the prospect of Brussels negotiating on the principle receding ever further, and the Foreign Secretary talking down the already vanishingly small chance of the treaty change which would be required to make such a change stick, a scenario in which she decides the deal isn’t enough to justify staying in is perfectly conceivable.

All of which increases the pressure on a certain blond bombshell, known to frequent the Uxbridge area, to make up his mind. As I wrote on Monday, Boris already risks frustrating the grassroots with his ongoing but unconsummated flirtation with Brexit. Further speculation that the Home Secretary might be preparing to declare first could yet force his hand.