It would retain the ability to further top up or decrease MPs' salaries in the future when there were changes to other benefits, such as travel or allowances.
However, the Green Party has argued the proposed formula could end up giving MPs even larger pay increases than in the past.
The party produced research showing that if the formula had applied over the past few years, they would now be on an even higher rate.
Co-leader Metiria Turei said the Greens were not convinced it was a fairer way to set MPs' pay.
"What's needed is a completely different approach, such as pegging MPs' pay to movements in the nominal median income. Instead, the Government is scrambling to pretend that its making a meaningful change to MPs' pay, without really making a difference at all."
Prime Minister John Key has countered that by pointing out that public servants got higher overall wage increases over that period because The Remuneration Authority had agreed to freeze MPs' salaries and allow only minimal increases during the global financial crisis.
Labour's Chris Hipkins and Annette King cautioned against rushing the bill through, saying while they supported a measure that would ensure MPs' increases were in step with other workers, there was no guarantee that would be the case.
Ms King said Labour would also push for state sector CEO pays to be restrained, saying it was getting too far out of step with the people who worked for them.
They also criticised National for providing the background materials on the bill too late for other MPs to digest them before the bill was debated.
Maori Party co-leader Marama Fox also said she was sceptical about the effect.
"The proposed changes the Remuneration Authority put forward were embarrassing, not because I don't think MPs deserve it.
"It's embarrassing because actually, so does the rest of New Zealand. The rest of New Zealand deserves to have a pay packet that adequately pays them for the job they do."
