Bill C-377 -- put forward by Conservative MP Russ Hiebert -- would reveal how labour groups use funds collected through union dues.
"Unions have a very valuable service that they provide to Canadian workers, ensuring they get proper care, safe working conditions and proper compensation for the work that they do. When Canadians see this kind of transparency, it will increase confidence in these organizations," Russ Hiebert said.
Some union leaders say their books are open for members to read.
"They have the audit available at the union offices and announce in their newsletters that they are there, and members can peruse it in the office," said Patrick Dillon, with the Provincial Building and Construction Trades Council of Ontario.
He is also a major player with the group Working Families, which created anti-PC ads in the last Ontario election, and says reporting the spending to the feds will cost a lot.
"Unions are people. If there is an expense for a union, there is an expense for the workers. This is a major attack on the unionized workers in this country," he said.
Dillon said that complying with the bill wouldn't simply mean scanning the already completed paperwork and posting it online.
Hiebert said he's been working on his legislation for two years and based it on the way charitable organizations are treated.
"I am not clear why they would be concerned about accountability and transparency. It's hard to be against those things."
The printed version of the bill looks like standard accountability legislation, reporting spending and dates. The political side effects, however, could cause some divisions within labour unions as members who pay their dues may not approve of the political direction of the leadership.
Some watchdog groups say that's not good enough.
"I have been on lots of union websites looking for this level of disclosure, and I have never seen it, even when a member hands me a copy of what he got at a bi-annual meeting, they don't have nearly the disclosure that is called for in this bill," said John Mortimer, President of the Canadian Labourwatch Association. "Canadians need to be allowed to evaluate the special kind of treatment that unions get."
The bill has passed second reading and is before the finance committee.
Contact your local MP or MPP in your area.