I heard on the radio this morning that the amendment would "pave the way" for a bill if it pass.
However, Labour has just announced that it is prepared to back a new Brexit referendum. I think it is looking likely now that Cooper / Letwin vote will pass and a second referendum will happen. Personally, I think this is the least bad of all the options.
Labour has also missed a trick I think. If they were prepared to back a new referendum before the no confidence vote, then May might have been toppled. A Corbyn led Labour government is .... 😱 😢😭💀