Parliament voted on the matter of constitutional principle, if you believe that they voted on the basis if Brexit then you are more naive than you appear to be already.
Then I have as much knowledge about the subject as UKGov then, which appears to be the square root of fccuk all.
I do know that it isn't the chequers deal that is what BS TM and the BBC are pushing again today,
https://www.bbc.com/news/uk-politics-45385421 chequers is not Brexit, it's laughable that TM is making out that it is, so you see, there are no Brexiteers delivering on Brexit, there are only remainers attempting to push forward on something that ain't Brexit, capiche ?