As many as 16 of the 48 people so far appointed to the tribunal donated money to the party, riding associations or candidates, according to Elections Canada records. None of the appointees appear to have given money to any other political party.
The finding emerged as the Conservatives faced another barrage of questions in the House of Commons on Monday over the appointments.
Questions first arose last week after The Canadian Press revealed that as many as one of every five appointees to the Employment Insurance Boards of Referees — which are now being phased out — ran afoul of federal guidelines for political donations by giving money to the Conservative party during their terms.
But now questions are being raised about the new Social Security Tribunal, which will eventually replace the EI referees boards when they are wound down.
The EI referees boards will continue to hear appeals filed before April 1. The three-person boards — made up of a government-appointed chair and workers' and employers' representatives — will decide on those cases until Oct. 31, at which point the unheard appeals will be transferred to the new tribunal.
The new tribunal will also hear appeals from Canada Pension Plan and old-age security claimants.
The Social Security Tribunal appointments are full-time jobs that come with hefty salaries.
Most full-time members of the new tribunal earn between $91,800 and $107,900, while some earn between $105,900 and $124,500. Vice-chairs earn up to $164,600, while the chair makes up to $231,500.
The Conservatives insist all appointments are based on merit. Jan O'Driscoll, a spokesman for Human Resources Minister Diane Finley, repeated the line the government has been using to respond to questions about patronage appointments.
"Our government makes appointments based on merit," O'Driscoll said in an email.
"The members appointed went through a rigorous selection process. They had to meet specific competency criteria required to do the job and have experience with the appeals process."
However, the Conservatives have yet to directly address the issue of apparently improper political donations made by members of the EI referees boards.
The Tories also used their majority on a parliamentary committee to put the brakes on an NDP motion to look into appointees to the Social Security Tribunal with Conservative ties.
New Democrat MP Chris Charlton had asked the House of Commons human-resources committee to look into the appointments at its next meeting, on Tuesday. But a notice for that meeting shows the committee will be discussing opportunities for older persons in the workforce instead of the appointments in question.
Minutes from the committee's last meeting show MPs went behind closed doors to discuss "committee business." Because committee members are not allowed to talk about what happens during the so-called in-camera portions of their meetings, it's unknown if that's when the Conservatives used their majority to vote down the NDP motion.
Last week, the committee had a chance to grill a senior official at Human Resources and Skills Development Canada about the appointments.
Ron Parker, the department's associate deputy minister, told MPs that 716 people applied for the Social Security Tribunal jobs. Of those, he said 162 eligible candidates were forwarded to Finley for consideration.
"So out of 716 people, the pool was winnowed down to 162 for up to 70 positions," Parker said.
"So I think the process was extremely rigorous, was based across all of the criteria that were published, such as many levels of knowledge and abilities, and a capacity to work effectively."
Meanwhile, the NDP has identified 10 appointees to the Social Security Tribunal with Tory ties, including failed federal and provincial candidates, members of riding associations and a former Nova Scotia cabinet minister who served in a provincial Progressive Conservative government.
During question period on Monday, Charlton again took the Conservatives to task over the appointments.
"I have said it before and I will say it again: Who you know in the PMO is not merit," she said.
"Despite clear rules that board chairs are not supposed to engage in political activities, it is reported that at least $37,000 was donated to the Conservative party for members of the soon-to-be defunct EI board of referees.
"Instead of punishing their appointees for breaking the rules, the Conservatives rewarded some of them with yet another plum patronage appointment to the Social Security Tribunal."
Conservative MP Kellie Leitch, Finley's parliamentary secretary, responded by insisting that the appointments are based solely on merit.