The mother of a Nova Scotia toddler in desperate need of a kidney transplant is calling on the federal government to change organ donation rules to presume people are willing to donate their organs in cases of accidental death unless family members say otherwise.

Canada鈥檚 demand for organs is outpacing supply by about 10 per cent, according the Canadian Transplant Society. They found 90 per cent of Canadians support organ and tissue donation, but less than 20 per cent have made plans to donate -- a discrepancy that may suggest the current opt-in rules are at the heart of the shortfall.

The 鈥減resumed consent鈥� model is already in place in a number of European countries, including Spain, Austria and Belgium. Wales, which introduced the system in 2015, has seen donation rates climb by 24 per cent.

鈥淚t looks like a trend which we hope will be sustained and which we hope we can build on,鈥� said Dr. Frank Atherton, chief medical officer for Wales.

Ashley Barnaby鈥檚 two-year-old son Zaccari was born with congenital nephrotic syndrome, a rare and life-threatening disease that causes swelling in the body. Zaccari鈥檚 kidneys have failed, and he requires dialysis three times per week at the IWK Health Centre in Halifax.

His only hope for a normal, healthy life is a donated kidney, but wait times can range from two to five years.

鈥淪preading the word about organ donation, and being his advocate is the only thing I can do right now,鈥� Barnaby told 麻豆传媒. A Change.org petition that she created calling for the rules to be amended attracted 4,498 supporters.

Last month, Saskatchewan Premier Brad Wall expressed desire to make his province the first in Canada to adopt presumed consent. Saskatchewan has the lowest organ donation rates in the country.

鈥淢y personal view is, if it's possible to have presumed consent that's consistent with the rights of Canadians and the Constitution, I think that would be a great thing to lead the country in,鈥� Wall said on Nov. 29 at the legislature in Regina.

A recent committee in Saskatchewan didn't endorse the concept. But officials from Wall's office told 麻豆传媒 that the idea of presumed consent is still very much "alive," suggesting it will come up for discussion again.

Critics of the practice-worry presumed consent could lead to organs being harvested against a family鈥檚 will. Some agencies believe more work needs to be done first at the hospital level- to promote organ donation by working with families of potential donors.

鈥淭here are other priorities at this time that will make a more immediate and bigger impact on improving those rates, which are at a crisis level at this point in terms of a shortage of organs,鈥� said Elizabeth Myles, the national executive director of the Kidney Foundation of Canada.

But in Wales, health officials say 40 per cent opted to become donors and only 6 per cent of people officially opted out of the program. That leaves the rest 鈥� 54 per cent -- as "presumed" donors

The Canadian Transplant Society estimates one donor can benefit more than 75 people and save up to eight lives.

Zaccari's mother said she doesn't understand the opposition to the concept.

鈥淵ou can opt out if you feel that strongly about not being an organ donor,鈥� said Barnaby. 鈥淏ut I鈥檝e always been brought up to believe that if you can help somebody else, why not?鈥�

With a report from CTV's medical specialist Avis Favaro and producer Elizabeth St. Philip