Dante
Average bang
'4' isn't going to happen.Surely the only real options, not all mutually exclusive, are
1) Negotiate a delay - this would require a better reason that "we want to keep bickering about what colour unicorn to ride to backstop negotiations".
2) Withdraw A50
3) New referendum (with or without a GE first)
4) No deal exit
Renegotiate backstop isn't one of those options. The EU may have mentioned this before.
'1' is just kicking the can down the road.
That leaves '2' and '3' as the inevitable choices, whether they happen with or without '1'.
I don't think any Parliament can unilaterally take option '2' without instigating a massive riot. '3' is looking more and more like the only feasible way out. It could even be sold as a Dunkirk style tactical retreat if they wanted to appeal to WW2-obsessed sensibilities.
The current political machinations are just about setting the groundwork for the Government to be able to go back the the British people with an excuse for their failures.
The bottom line is that the UK electorate voted for our politicians to try and come up with an exit plan. They made that attempt but not without a few huge question marks. It's only sensible to democratically ask the public for a further steer.