But isn't this in many ways actually even more risky?
When Parliament gets its vote, the two year exit period will almost certainly be almost over and a vote of Parliament will not be able to stop the exit. Instead it will be a vote on the new arrangements with the EU. So either they just have to rubberstamp whatever gets put to them or - if they vote down these new arrangements - Britain will be left outside of the EU without any new deal in place.
When Parliament gets its vote, the two year exit period will almost certainly be almost over and a vote of Parliament will not be able to stop the exit. Instead it will be a vote on the new arrangements with the EU. So either they just have to rubberstamp whatever gets put to them or - if they vote down these new arrangements - Britain will be left outside of the EU without any new deal in place.