You think Labour will back a deal rather than take the opportunity to bring down the government? Why? They haven't so far.
Equally, the ERG increasingly sees No Deal as the least worst option and it's looking like a deal isn't possible. Largely unnoticed the other day, the ERG slipped in an amendment to the Chequers Bill that effectively destroys the backstop clause for Northern Ireland, regarded as the guarantee there’ll be no hard border with the Republic. If that's the case, all bets are off. That would put in jeopardy the entire Withdrawal Agreement - which if it collapsed would mean a no-deal Brexit becomes virtually certain.