continuity I beg to differ - I could of course be wrong which is why I think there will be a court case.
My understanding is that the Bill cannot compel the Executive (Government) unless it exercises prerogative power. This means it needs Queens consent, contrary to Bercow.
"Sir,
The power to extend Article 50 is either a prerogative power, or it is not.
(a) if it is a prerogative power, the Benn-Burt bill (a.k.a. the βStop Brexit Billβ, which orders the Prime Minister to seek yet another Brexit extension) requires Queenβs Consent before it can become law;
(b) if it is not a prerogative power, the UK already left the EU on 29 March 2019. This is because in that case, the then Prime MinisterTheresa May would have lacked authority to extend Article 50. No relevant primary legislation was enacted or amended prior to that date to enable her to do so.
...
The Speaker has ruled (see here) that the Benn-Burt bill does not require the Queenβs Consent but he cannot have it both ways: either it does, in which case it requires Boris Johnson to advise the Queen to grant it, or it doesnβt, in which case the UK has left the EU already."
independencedaily.co.uk/letters-to-the-editor-saturday-7th-september-2017/
FWIW I disagree with point b in part. Again there is ongoing legal discussion on this. My understanding is that Theresa May exercised her prerogative power to extend Art 50 acting on the advice of Cooper-Letwin.
The fact that the Govt has no majority takes away any implicit assumption that Parliament and Government can be conflated, although I think that would be a very outre interpretation in any case.
It is not the case that Parliament can make any laws it likes and they are then watertight. Constitutional safeguards are there and open to the courts to uphold. This is one of those cases. Why? Ask yourself if it would be OK for Parliament to decide to compel the PM to declare war on someone against their judgement?