There are a handful of big things to watch out for following Sir Philip Rutnam’s resignation as Home Office Permanent Secretary:

1. Whether in laying out his case for constructive dismissal, evidence emerges that makes it impossible for Priti Patel to remain as home secretary.
2. Whether other permanent secretaries and senior civil servants show solidarity with Rutnam, thus making it harder for Dominic Cummings to reform how they and civil servants support the Government, and harder for him to streamline the centre of government and the Cabinet Office.