People who complain about this and misinformed voters make me laugh. The whole point of this bill is to be as narrow as possible to authorise the govt to exercise article 50. It's only ~20 lines so it's narrow scope will pass the lords. It's got nothing to do with EU citizens rights or £350m to the NHS. Those tabling amendments are basically trying to filibuster.
Trying to constrain the government when it follows through on 'the will of the people' is not filibustering. The fact is that, so far, Theresa May has shown herself to be nothing more and nothing less than a ruthless opportunist who embodies the absolute worst of populism.
There is a huge chunk of the UK population that is full of rage, and wants us to leave the EU, along with literally anything prepended by Europe. Despite making it extremely clear prior to the referendum that she believes Britain's best interests are served inside the European Union, she is now wiling to throw the baby out with the bathwater merely because it's politically convenient. She is willing to use EU residents as bargaining chips, is downright aloof when it comes to the problems posed by Northern Ireland, is making it eminently clear on a daily basis that she couldn't give a damn about the damage this will likely do to our country and its economy.
MPs want to try and keep some semblance of sanity, to prevent her from doing whatever the daily mail asks her to do next... that's not filibustering.