TD Securities' analysts note that the UK government has confirmed that it's requesting to prorogue parliament from around September 11th until the Queen's Speech scheduled for October 14th.

• “Downing Street is selling this as a "bog-standard" prorogue, in line with what normally happens before a Queen's Speech. However, the timing is obviously rather convenient for a government that wants to thwart any attempts by the opposition to take control of parliament and rule out a no-deal Brexit.
• So parliament sits as normal next week, and we can expect opposition parties to be putting all efforts toward passing some sort of legislation to prevent No Deal Brexit, if not calling an outright confidence vote (and it's very unclear which way that confidence vote would fall).
• We think that there are two main implications: 1) This reduces the odds of the Parliament forcing a Brexit deadline extension on the government. 2) With parliament less likely to be able to stop a no-deal Brexit, this increases the odds that the EU is willing to bend on re-opening the Withdrawal Agreement, and that the UK leaves the EU with a deal on 31 October."