Nominations close on June 15th.
Final two candidates by June 30th
Full membership ballot by summer recess (mid July)
We know there's going to be an election, and a referendum. The legislation for a referendum, and then the vote itself some months later.
I'm just trying to get exactly the order of events.
Queen's speech in September with a referendum in it.
Hold the government together for six more months. Referendum in March. Remain wins, General election in June.