Napier Labour MP Stuart Nash says Green Party co-leader Metiria Turei's revelation that she once committed benefit fraud is "problematic" and she should immediately pay the money back.
Ms Turei made the admission when announcing the party's welfare reforms at the weekend.
She said that when she was a solo mum 24 years ago she did not tell Work and Income about the extra flatmates who were paying rent in her house.
Mr Nash said it was an unusual move for someone who wanted to lead the country.
"She knowingly lied and I find that problematic.
"She should pay the money back immediately with interest, especially considering there are people out there working very hard, paying their bills and doing everything by the rules."
When asked if he had ever received a benefit, or Working for Families, he said he had not, and this was the case for most of the local candidates standing in this year's general election, but not all.
Green Party candidate for Napier Damon Rusden said he had received benefits over the years, including student benefit, and that it took a lot of courage for Ms Turei to admit her past behaviour.
"She did this to highlight that our welfare state is not supporting those who are most vulnerable - and it shows people can be forced to lie or have their benefit cut.
"It takes a lot of bravery to do what she did."
Napier's National candidate David Elliott said he was once on the unemployment benefit for two weeks when he was 18 years old.
"I had been doing flying training but ran out of savings so I went looking for work and got the radio announcer job at 93FM."
National's Tukituki candidate Lawrence Yule said that his personal records for the past seven years showed he had not received any benefits, nor Working for Families, during that time.
To his knowledge he did not receive any such support before that time, but he said he would have to go back through all those earlier records to be absolutely sure.
Wairarapa National MP Alastair Scott dismissed Ms Turei's confession as "attention-seeking".
He said he had never been on any sort of benefit himself, and did not qualify for Working For Families support.
"I don't know what she's trying to prove other than grabbing attention.
"She has ripped off the system - does she want a medal for it?"
Wairarapa Labour candidate Kieran McAnulty said he was uneasy about the question and whether it was in the public interest.
"Having received a benefit previously, or doing so currently, is in no way a reflection of a candidate's electability," he said.
Of the other candidates who were able to respond before deadline, Ikaroa Rawhiti MP Meka Whaitiri said she had never received any benefits or Working For Families and Democrats for Social Credit Napier candidate Karl Matthys said he once received the unemployment benefit for a few months.