Gavin Barwell was spotted in St Pancras this morning getting off the 8.52am Eurostar from Brussels – complete with overnight bag and accompanied by an unidentified aide. A co-conspirator says Barwell was looking very pleased…

The PM’s Chief of Staff hasn’t been a regular visitor to Brussels during the negotiations so far and his visit wasn’t briefed out to the media. What could he have been up to?

UPDATE: A Whitehall insider has identified the aide as Barwell’s private secretary.