Well one things for sure MP's can't win!
If they go with their conscience and vote for action or not for action in Syria they will be 'hounded' by both sides .
If they go with their conscience and vote to trigger or not to trigger Article 50 they will be 'hounded' by both sides.
It's a tricky question when there is a 3 line whip but if an MP feels so strongly about something he/she should be given some slack to vote with their conscience and go against the whip.
As I say they 'can't win' because they will never please their party or their constituents all of the time.
I don't envy anybody who chooses to be an MP to be honest and the level of abuse , especially personal abuse, has risen I would hazard a guess due to the ease of some pretty hateful people hiding behind the shield of anonymity.