David Davis, has behaved very shrewdly and has spiked the guns of the people who wish to reverse the referendum result.

The wrecking crew in parliament can now have their vote on whatever deal is available and if it is not to their liking, Britian will leave the EU and operate as a sovereign nation under WTO rules.
This has the added advantage that if in the unlikely event of something going wrong, it can be blamed on the bloody mindedness of the "remainers" in parliament and their cheerleaders in the country.

Checkmate.