Six such members have left the tribunal since its inception in April 2013; the government says they have quit due to personal reasons.
Hundreds of people have applied for current full-time and part-time openings on the tribunal, which has an allotted 74 full-time members who can each earn as much as $109,000 annually.
The ex-member, speaking on condition of anonymity for fear of reprisals, left in part because the government doesn't provide basic benefits similar to those provided to other government-in-council appointees.
"Government-in-councils have a standard number of benefits they're given in lieu of the fact that they have to divest themselves of a number of stocks, bonds, mutual funds, certain investments," the individual said in a recent interview.
"Normally, the government provides disability insurance in case you get hurt, you get a pension or contributions towards a pension because you are making less than you would in the private sector, and you get medical and dental benefits, which are pretty standard nowadays.
"But in this situation, they provided nothing."
The tribunal hears appeals from thousands of Canadians denied employment insurance, Canada Pension Plan and old-age security benefits. It is currently struggling with a 10,000-case backlog.
The government is upfront about the fact tribunal members don't receive benefits, said Alexandra Fortier, a spokeswoman for Employment Minister Jason Kenney. Job postings for both full- and part-time tribunal members make clear no benefits are paid, Fortier noted Thursday in an email.
That's likely discouraging top-notch candidates from applying, given they can earn more money, with better benefits, in the private sector, the former member said. They're also kept away by "onerous" government-in-council regulations that require them to substantially divest themselves of certain investments.
"I understand that the regulations are necessary, but at the same time, we are not decision-makers. We don't have any inside information, we are simply arbitrators, and we have to divest ourselves of stocks, certain bonds, mutual funds of a particular type."
Meantime, many powerful senators sit on the boards of energy companies and other major corporations, said the former member, who called it an "absurdist situation."
"If they want individuals that have a particular skill set to make those sorts of complex decisions, they're not going to attract them this way. I think that's the reason people like me have resigned."
Rodger Cuzner, the Liberal employment critic, said such complaints aren't surprising.
"In today's world, you have to compensate good people and that's who you want to draw to those positions," Cuzner said.
"If the lack of basic benefits is a cost-cutting measure, it's a huge disservice to the program and the people it's supposed to serve. It's another kick in the pants to Canadians who are most vulnerable."
Several of the tribunal's 72 full-time members previously donated money to the Conservative party. The new panel replaced several other separate boards that heard appeals on social security rulings.
The government has made good on a promise to save taxpayers more than $20 million a year under the new system. But the tribunal is also hearing fewer appeals as it tries to plow through thousands of old cases.
The former tribunal member said there's also pressure to hear cases at too fast a pace. The feds, meantime, have hired 22 part-time employees to help the backlog of Canada Pension Plan disability and old-age security cases.
Follow Lee-Anne Goodman on Twitter @leeanne25