They also said Mr McClay didn't give them the opportunity to consult with their caucuses over their reports on the bill.
Labour's SOE spokesman Clayton Cosgrove said National's actions amounted to "an abuse of process" that was disrespectful to submitters.
"It breaks every democratic protocol, the National Party may as well have said to submitters we don't give a damn what you say, we're not here to listen we've already made up our minds, we're not even going to respectfully consider your view, it's a done deal."
Greens co-leader Russel Norman said the process had been "very undemocratic".
"It's been very rushed, there hasn't been proper consideration of the submissions or the concerns raised in the submissions. We've had inadequate information from Treasury because they haven't had enough time either."
Given the original July 16 reporting date, "it's not as if we were short of time".
"Obviously the Government's trying to rush it through for political reasons because it's a hot potato."
Mr McClay said July 16 was only the deadline, "the committee was able to get through its work before that time so we deliberated on it today".
He rejected the opposition claims it was a rushed process saying there had been eight meetings where 150 submissions were heard.
"This is a political issue Opposition parties for many many months have been expressing their position on this they're not in favour. I accept that but sooner or later as this is part of the Government's agenda to modernise to economy a decision had to be made and today was the day the committee chose to make that decision."