A lot of people have said that since the Letwin amendment has passed it has scrapped the possibility of there ever being a 'meaningful' vote on Johnson's deal.
Why is this so?
It's not an accurate description. What is true is that Bercow just dismissed the government's attempt to pass the deal by motion again. (Web confirmation.)
The deal can still pass by legislation (instead of motion). The government has announced that they will introduce deal legislation today. When it will be voted on is another matter.
The Letwin amendment substitutes the MV motion with the bigger hurdle of legislation, but does not eliminate a vote on the deal.
Rees-Mogg just announced that the 2nd reading of the bill will happen tomorrow. That normally entails a vote on substance of the bill/deal, although it's not necessarily the final vote on the bill. (The opposition is already objecting on the tight schedule of that 2nd reading.)
It's not a case of they won't ever be able to vote again on the deal.
The amended motion says that consent will be withheld until the Withdrawal Agreement Bill becomes law. In that respect, when it does become law, then MPs can hold another vote to formally approve it.
(Note: It is possible that the Withdrawal Agreement Bill may contain provision to say that the "Meaningful Vote" is no longer necessary, in which case, the "Meaningful Vote" will effectively be the third reading of the bill.)
The rule of parliamentary procedure is that a motion (or similarly worded motion) may not be put twice in the same parliamentary session unless circumstances have changed. That is why Speaker Bercow ruled the attempt to have a meaningful vote on Monday 21st October out of order.
However, if the Withdrawal Agreement Bill were to be passed, circumstances would very clearly have changed (the condition in the Letwin amendment would be satisfied), and the Meaningful Vote motion could be brought back to the House and would almost certainly be ruled in order.
Thus it is not correct to say that there can never be a Meaningful Vote on Johnson's deal - just not yet (and probably not before 31st October).