In their political beliefs, Toronto Liberal Nathaniel Erskine-Smith and rural Saskatchewan Conservative Cathay Wagantall appear to be worlds apart.

They've got this much in common, though: they're using private members bills to challenge where their parties stand on some very awkward policy topics — and pushing their respective leaders into some public discussions they'd probably rather avoid.

Private members bills — legislation proposed by individual MPs — have long been used by backbenchers to push personal causes or make policy arguments without official seals of approval from party leaders or cabinet.

Conservative MP Cathay Wagantall is proposing tough penalties for doctors found to have performed sex-selective abortions. (Steve Fischer/CBC)

Late last month, Wagantall tabled a bill that would send doctors to prison for performing sex-selective abortions — terminating a pregnancy because of the fetus's gender. During the fall election campaign, Conservative Leader Andrew Scheer said it was his responsibility to ensure that his party does not re-open the abortion debate.

Erskine-Smith has been a bit more cagey in his pitch to change the laws on hard drug use.

Prompted by the opioid crisis, he has two pieces of legislation at the ready — one that would decriminalize all drug possession and a second bill that would take what he calls the "lesser step" of giving police the option of issuing a warning to individuals caught with illicit drugs, or of referring them to a health care provider.

Prime Minister Justin Trudeau rejects the idea of legalizing hard drugs. 0:19

Erskine-Smith will soon have to pick just one bill to put forward for a vote. In principle, he said, he favours the first bill — but he acknowledges the second would be an easier sell.

"I recognize the politics. I recognize that my government has not indicated support and has in fact indicated opposition to decriminalization," said Erskine-Smith.

That opposition comes from the top. Asked earlier today about Erskine-Smith's proposals, Prime Minister Justin Trudeau said he'll "take a look" at them — while shutting the door on sweeping decriminalization in almost the same breath.

"We believe in harm reduction and evidence-based policy. Our approach is to ensure people get the help they need. We do not believe that decriminalizing hard drugs is a solution right now," he said.

Blame game

Both bills are probably months away from a vote. Neither can count on enough backing to pass a Commons vote. But they're already being used as political weapons by Conservatives and Liberals both.

Minutes after Trudeau's comments, the Conservatives sent out a tweet attacking his remarks.

Justin Trudeau doesn't think the time to legalize dangerous drugs like heroin, crystal meth, and crack cocaine is "right now."<br><br>Then, when? <a href="https://t.co/JQ0k2ce31a">https://t.co/JQ0k2ce31a</a> —@OLO_BCO_Comms

That message continued earlier attempts by the Conservatives to pin Erskine-Smith's ideas on the prime minister.

"Justin Trudeau and the Liberals are looking to legalize hard drugs like heroin, crack cocaine and crystal meth," says a Conservative news release sent out on Tuesday.

(Erskine-Smith points out that he is not advocating legalization. Drug traffickers and producers would still be prosecuted under his proposals.)

Both the Liberals and Conservatives are engaged in a sort of Twister version of the old blame game — attacking their opponents for proposals coming from the back bench while bending over backward to avoid being held accountable for their own MPs' bills.

Scheer not ruling out support for abortion bill

The Liberals have been eager to present Wagantall's bill as evidence of an under-the-radar Conservative quest to undermine access to abortion services.

"Clearly what the Conservative Party has been saying throughout the last month is that they were willing to reopen the debate," Minister of Economic Development and Official Languages Mélanie Joly told reporters last week.

"As leader of the Conservatives, Mr. Scheer has always discouraged members of his caucus from introducing items that will open this debate," says a statement from Scheer's spokesperson, Simon Jefferies.

Jefferies also took care to avoid driving a wedge between the party and voters who support Wagantall's position, noting that Scheer is personally opposed to abortion and, like a great many Canadians, "finds the practice of getting an abortion specifically to avoid having a baby girl abhorrent.

"This will be a free vote within the Conservative caucus."

Jefferies did not respond to specific questions about how Scheer would vote on the matter.

It's entirely possible the bill will not come to a vote until the fall, by which time Scheer will have been replaced by a new Conservative leader.

'Absurd' attack

Erskine-Smith said the finger-pointing over private members bills can make it difficult to have a credible conversation about public policy.

"I think it is unfortunate politics both ways if we suggest the initiatives of backbenchers are official party policy or official government policy," said Erskine-Smith.

"I think we should welcome private members bills that advance serious conversations in a sensible way."

I regularly expect our politics to be better than this. And I am regularly disappointed. <br><br>The bill in question, which the government has not indicated support for, would only decriminalize possession for personal use. <a href="https://t.co/3WZPxctK2k">https://t.co/3WZPxctK2k</a> —@beynate

Erskine-Smith pointed out that the Canadian Mental Health Association, the Canadian Public Health Association and public health officials in British Columbia and Toronto have all called for some form of drug decriminalization. He also questioned whether Wagantall's bill enjoys the same level of expert consensus.

CBC News asked for an interview with Wagantall. While her office confirmed the request was passed on to her, she did not respond by time of publication.

Erskine-Smith, meanwhile, said he finds the politicization of the whole debate disappointing.

"Maybe it emphasizes the difficulties of discussing sensible drug policy in a serious way in Canada."