The Liberal government is facing a new push to end a ban on blood donations by sexually active gay and bisexual men — a policy that Justin Trudeau's own election platform called discriminatory.

An electronic petition recently filed with the House of Commons, E-1589, calls on the Liberal government to stop a practice it says imposes a stigma on gay and bisexual men. Petitioners say the policy also bars Canadian Blood Services — which routinely faces donor shortages — from a potential pool of healthy, safe donations.

Under current CBS policy, any man who has had sex with another man in the past year is prohibited from donating blood.

"If you're a heterosexual male with unprotected sex with multiple partners, you're free to go in and donate blood. But ... if you are a gay or bisexual man, you are required to be celibate," said Annette Toth, a B.C. union leader who launched the petition. She said CBS is involved in "fearmongering."

Toth said her union became seized with the issue after discussing a blood drive as a possible charitable activity. One union member advised his colleagues that, as a gay man, he was banned from donating even though he had been in a monogamous relationship for more than a decade.

The 2015 Liberal election platform promised to end what it then called a "discriminatory ban."

In 2016, the government lowered the deferral period, clearing gay and bisexual men to donate blood after abstaining from sex with other men for one year, instead of five. But it did not eliminate the ban. Instead, it set aside $3 million to fund research on behaviour-based donation policies.

CBS Chief Scientific Officer Dana Devine said the agency hopes to change its screening process, but needs time to carry out the necessary research.

Vials of blood wait to be tested at the Canadian Blood Services clinic in Halifax. (Nic Meloney/CBC)

Risky vs. not risky behaviour

Devine said CBS believes there should be a way to distinguish "risky sexually-active gay men from not risky sexually-active gay men.

"That's the premise that we're operating on for trying to be more inclusive for people who should be eligible to donate blood," she said.

Much of the CBS's current research is focused on how to ensure maximum clarity in the screening process, so that questions are carefully worded and properly understood by prospective donors.

"We have to be able to show that if we stand up a set of questions that are behaviour-based, that they actually get the right information," Devine said.

She said it likely will take CBS until early 2020 to wrap up the research and issue a proposal to government.

Ultimately, the decision is Ottawa's to make, through Health Minister Ginette Petitpas Taylor.

Trudeau 'a little disappointed'

After the deferral period was shortened but not eliminated, Prime Minister Justin Trudeau told the Daily Xtra, an online magazine that focuses on LGBT issues, that he was "a little disappointed" by his own government's policy.

"I understand that going from five years to one year is a small step in the right direction, but it doesn't make one whit of difference in the vast majority of people who would want to donate but are being prohibited from it," he told the publication in June 2016.

NDP MP Randall Garrison said Canada Blood Services' policy that rejects blood from sexually active gay men is discriminatory. (CBC)

NDP MP Randall Garrison said the government has the authority to kill any regulation which is no longer justified. He said he believes the government is buying time and deliberately pushing the issue past the next election.

"When this ban was introduced in the 1980s, we didn't have the science. It was an emergency measure that has completely outlived its usefulness," he said.

"Now, the risks to the blood system are from risky sexual behaviours, not from a category of people."

Limits blood supply

In addition to imposing a stigma on gay men, the policy runs counter to CBS's goal of having a safe and sufficient blood supply, Garrison said.

"We have shortages all the time, and by banning people from donating on the basis of their sexual orientation, we're simply decreasing the supply of blood that's available to everyone," he said.

A spokeswoman for the Conservatives said the party would reserve comment until the details of a government policy are made public.

Petitpas Taylor's office said in a statement that the government is "committed to ensuring the safety of our blood services and non-discrimination in donation policies.

"Through investments to Canadian Blood Services – in collaboration with Héma-Québec – we are supporting research that will allow us to work towards creating donation policies that are both safe and non-discriminatory."

Petipas Taylor's mandate letter, dated Oct. 4, 2017, calls on her to "develop a long-term vision for blood services that ensures safety and non-discrimination in donation policies."

E-petition 1589 also calls for improved policies on transgender blood donors. CBS said it is reviewing and improving its intake process for transgender donors.

The petition is open for signatures until July 17.