To translate it to American, it's a similar two party system as yours, and the UK Dems are the ones doing this.

Yeah unfortunately one vote every 4 or 5 years is not enough granularity to weigh in on specific issues. Also, politicians lie about what they will do all the time.

Showing that a large amount of people are against an action, whether by petition or protest, is one of the tools we do have.

This particular piece of legislation has been in the works for two administrations of two different parties. We're kind of sick of both of them so I think many people will likely vote for a 3rd party the next time around. Possibly the more progressive splinter group of our 'left" party.