Practically speaking, Greenpeace et al. DO have more standing than HM Loyal Opposition.  Special interest groups can armtwist governments through popular opinion and lobbying whereas the Opposition only has its vote in the HOC.  In a majority government, the Opposition vote is quite futile.

Observe the shameless brainwashing of our youth by the David Suzuki alarmist films screened in schools vs. what transpires during Question Period.  Which do you think wields more power?