Pay-fixing system gives parliamentarians vested interest in widening inequality, says party co-leader.
The Greens will push for legislation to lock MPs' and ministers' pay rises or even cuts to the same dollar amounts ordinary New Zealanders receive.
Co-leader Russel Norman said his party would seek a law change to ensure "that MPs' salaries are part of the solution to rising inequality, rather than part of the problem".
Last year, MPs' base salary rose 2.2 per cent or almost $3000 a year while the median income rose by just $780.
But Dr Norman said the independent Remuneration Authority was effectively obliged under current law to link MPs' pay to that of top earners.
"All percentage increases do is widen the gap between the middle and the top ... MPs and ministers have a vested interest in widening inequality so we want to change it."
Under the Greens' policy the Remuneration Authority would be obliged to raise or cut MPs' salaries by the same nominal or dollar amount as annual changes in New Zealanders' median income.
"Only when middle New Zealand is better off should MPs' salaries increase," Dr Norman said. "If middle New Zealand is in a worse situation, MPs should not get big pay top-ups."
The Greens had not discussed the policy with allies Labour but Dr Norman hoped public pressure could force the law change even without the Greens as part of the Government.
He cited their success in "forcing other parties into line" over declaring MPs' expenses and also in getting their home insulation scheme put in place by National.
But Labour leader David Cunliffe was no more than lukewarm on the Greens' pay proposal.
"The primary principle is that MPs' salaries shouldn't be set by MPs themselves - the Remuneration Authority is the appropriate body to do it," he said yesterday.
"I personally have no problem with them looking at median wages as a key indicator but I think a broader debate is required before we sign up to one indicator alone."