Thread by @Staedtler

From what I can see they're going to prorogue parliament between . . . ur . . . September 12th and reconvene on October 14th

Which was going to happen anyway for party conference

Parliament was going to adjourn between those dates anyway for conference season. It was set down weeks ago.
All that's new is that Boris Johnson has decided to start a new session when parliament comes back after conference.

But like I've been reminding you for a thousand years, you can only start a new session with a Queen's speech. Which has no chance of getting through.

Parliament is free to vote on all sorts of amendments to the Queen's speech in October, including asking for another extension or revoking Article 50 entirely.

Boris Johnson has just lost, but as usual everyone is so far up their own indignation that they haven't noticed yet.

Once you shut parliament, there's nothing the government can do. Anything that comes up that needs parliament to vote on it, the government is now stuck.

There's going to be some crisis or other during that month that parliament is away. And there's no way of recalling it because you have to have a Queen's speech, and that will never get through

As I would have warned Boris Johnson, and as Shorty Cummings obviously didn't, once you close parliament you lose control of events.
And with no majority to fall back on, Boris Johnson has just committed political suicide.

So. Johnson won't be able to get a Queen's speech through in October, or it'll be hit with so many amendments that half of his party will mutiny.
So when parliament does come back in October there's going to be a general election. With polling day in December.

If polling day is in December, did we leave Europe or didn't we? If we did we'll be in an economic crisis, and the Tories will lose.
If we didn't, the Tories will face a backlash from Brexiteers, and so they will also lose.

And that leaves only one option. Boris Johnson will have to table a general election himself in the first week back in September. That's the only way he can get an election before Brexit day.