It's a meeting that's so top secret that those attending - at a secret location - are ordered to surrender their mobile phone and any other el.
The meeting will take place on Friday with just one huge item on the agenda: agreeing the manifesto that Sir Keir is expected to present to the country on 13 June.
Former MP Lembit Opik predicts the DUP could lose up to a third of its Westminster seats because of the shock surrounding the sex charges faced by Sir Jeffrey Donaldson.