“Can things get worse for the government?” That is the question being asked in Westminster. The answer is: yes, quite easily.

Damian Green, Theresa May's deputy and her closest senior ally, is the subject of a Cabinet Office investigation into alleged sexual harassment and the possession of "extreme pornography". Should Green be forced to resign, it would be a grievous blow to May, far more damaging than Michael Fallon and Priti Patel's departures.

Since the loss of the Conservatives' majority, Green, a friend of May's since their Oxford days, has acted as May's political life support machine (as Peter Mandelson did for Gordon Brown). Though Green's departure need not be terminal for the Prime Minister (Amber Rudd would likely replace him), it would weaken her more dramatically than any event since the election.

Then, on 22 November, Philip Hammond will deliver his second Budget since becoming Chancellor. The first led to a briefing war between No 10 and the Treasury and one of the fastest – and most humiliating – U-turns in recent history (over an increase in National Insurance on the self-employed). Even if he avoids another major political error, Hammond risks provoking a new round of Brexit wars (should his speech be deemed insufficiently optimistic by Tory MPs) and disappointing those craving Keynesian interventionism (the Chancellor has so far rejected Sajid Javid's proposal of £50bn housing investment).

Finally, the European council meeting on 13-14 December will determine whether the UK can formally begin talks on a new EU trade deal. Should May be denied permission, the government will have little to show for nine months of negotiations. Tory Brexiteers would demand greater preparations for "no deal", while Remainer hopes that Brexit could be stopped would grow.

In the absence of an unanticipated scandal, or a voluntary resignation, May is still likely to remain Prime Minister. The fundamentals have not changed: Tory MPs cannot agree on an attractive alternative, the Conservatives are determined to avoid an early election (and a potential Labour victory) and, as Stephen noted this morning, the job of Prime Minister is becoming less desirable by the day. But the three events described above - the Green investigation, the Budget and the European council meeting - will determine whether May can end the year with something resembling dignity.