A decades-long battle to unseal Ontario adoption records will face yet another hurdle Monday when a small group of adoptees and birth parents mounts a constitutional challenge to the legislation.

A minority of critics argues the Adoption Information Disclosure Act — which allows birth parents and adoptees to access information about one another — presents a serious breach of privacy under the Constitution.

"We're saying that you can't retroactively undo the privacy that was promised to Canadians who gave children up for adoption or who adopted children," said Clayton Ruby, a Toronto-based civil liberties lawyer representing three adoptees and one birth parent who want their identities kept private.

"They want to continue living their lives without having an alcoholic mother drop in on them. Without having a child to harass them because they're angry about being put up for adoption. Maybe just because they value their privacy and don't want their life to change."

No choice to remain anonymous

Passed a year and a half ago, the legislation is expected to be fully implemented this fall, but it's not clear whether it will happen before or after the Oct. 10 provincial election.

While British Columbia, Alberta and Newfoundland and Labrador have all passed similar legislation, Ruby said those provinces have included a disclosure veto that protects the identities of those who wish to remain anonymous.

Ontario's law, he said, merely offers people the opportunity to sign a form indicating they'd prefer not to be contacted. While there are penalties for those who breach the order, Ruby suggested filing charges and going to court is a "very ineffective remedy."

And while the order may prevent someone from contacting their birth parent or the child they gave up years earlier, it doesn't stop them from communicating with their relatives or their employer, Ruby said.

"They can follow you around and see what your life is like," he said. "All that is perfectly legal."

'Great solace' in knowing parents: supporter

Michael Grand, a spokesman for the Coalition for Open Adoption Records, said it's unfortunate that a small group of people is seeking to take away the rights of thousands who want to know that their child is alive or that their medical ailment may be genetic.

"There's great solace even in knowing a name," said Grand, a University of Guelph professor who has done extensive research on adoption-related issues. "It's important because one needs that kind of history to build a sense of identity."

Grand said the Adoption Information Disclosure Act has far more provisions than many other countries to limit unwanted contact and protect the identities of those who may have been abused.

He said some 57,000 Ontario residents signed on to the adoption disclosure registry under the old legislation, compared to just two to four per cent of people who signed the disclosure vetoes in those provinces where such provisions exist.

Court case may distress many: Grand

"This is a minority," he said. "I can only hope that the court case does not succeed because it will bring great pain and distress to so many thousands and thousands of people in Ontario who desire to know more about how they came into this world."

But Ruby said the Constitution's very purpose is to protect minorities.

"That is why we have a Constitution," he said. "Majorities need not protection from itself. Politicians listen to majorities and that's what they did in this case."