Wellington – The co-leader of New Zealand's Green Party resigned on Wednesday, three weeks after confessing she committed welfare fraud as a struggling young mother more than 20 years ago.Metiria Turei said the scrutiny on her family following her disclosure had become unbearable and she worried she was hindering her party's chances six weeks ahead of an election.Polls indicate support for the Green Party has plummeted since Turei's confession and the appointment last week of Jacinda Ardern as opposition leader.The liberal Green Party is the nation's third-largest party, with 12 seats in the 119-seat Parliament. It will now run its campaign with a single leader, James Shaw.Turei made the confession as part of an attempt to energise debate about the difficulties of living on welfare, at the same time pledging to raise benefits by 20%.A Newshub-Reid Research poll on Wednesday indicated support for the Green Party had dropped from 13% to 8% over the past two weeks while support for Ardern's Labour Party had leaped from 24% to 33%.ScrutinisedSupport for the governing National Party edged down a little to 44%, according to the poll. Under New Zealand's proportional voting system, parties must typically form alliances to govern.At the Green Party's annual meeting last month, Turei, 47, said that when she was a law student, she didn't have enough money to pay her bills while raising her daughter. She said she lied to authorities about how many roommates she lived with, because the truth would have lowered her accommodation entitlement.Many political commentators at first described her confession as a bold and effective move. But as reporters and rivals scrutinised her claims, Turei admitted she'd also falsified her voting address and at one point lived with her mother as a roommate.Earlier this week, two Green Party lawmakers said they wouldn't seek re-election because Turei had not resigned. Turei said as late as Wednesday morning she had no plans to resign, but then changed her mind and will leave Parliament. She had been a lawmaker for 15 years."I am confident that if I step aside from the co-leadership, that the Green Party will have the best possible chance of improving our vote and being part of the next government," she said.