Attorney General David Lametti and Crown-Indigenous Relations Minister Carolyn Bennett are demanding the Conservative leader in the Senate put an end to procedural manoeuvres by his caucus that threaten to derail legislation to implement the United Nations Declaration on the Rights of Indigenous Peoples (UNDRIP) in Canada.

In a letter to Conservative Senate Leader Larry Smith, Lametti and Bennett said "stall tactics" employed by Conservative senators — such as adjourning debate, a tool used to punt a vote or delay further discussion — are blocking Bill C-262 from getting a timely study at the Senate's Aboriginal Peoples committee.

UNDRIP recognizes the right of Indigenous peoples to legal equality, self-determination, the preservation of their languages and control of their traditional lands, among other rights.

"Reconciliation with Indigenous Peoples cannot and should not be subject to partisanship," the ministers said. "We write to you not only as ministers of the Crown ... but as Canadians who share a deep commitment to advancing reconciliation with Indigenous peoples ...

"We are calling on your Senate caucus to cease its procedural delay tactics and allow this bill to move to the appropriate committee."

Smith and Conservative party whip Don Plett have sought to push off a vote on sending the legislation to committee. Some Conservative senators, including Sen. Scott Tannas, have expressed reservations with the bill — particularly with a provision of UNDRIP that calls for "consent" from Indigenous peoples before a project on their traditional territories can go ahead.

"I support the UNDRIP in its entirety, with the exception of the word that gives me heartburn, which is 'consent,'" Tannas said during a recent Senate debate.

"What does that mean? ... If it turns out that consent equals a veto or anything approaching a veto for Indigenous people over activities and projects affecting their traditional lands, then we need to know that before we vote on this bill and bring it into law," the Alberta senator said.

Indigenous activists have long pointed to UNDRIP as a means to oppose pipeline development that would run through their territories, pointing to the passage that guarantees "free, prior and informed consent" as something akin to a veto. Other scholars insist that UNDRIP does not grant Indigenous communities a final say.

The letter to Smith comes a day after the House of Commons unanimously passed a motion — with the support of Conservative MPs — urging the upper house to pass "at the earliest opportunity" both Bill C-262 (the UNDRIP bill) and former Conservative MP Rona Ambrose's legislation that demands mandatory sexual assault training for judges. Both bills have been before the Senate for more than a year.

Indigenous leaders, including Assembly of First Nations National Chief Perry Bellegarde, have condemned the Senate delays as "undemocratic."

Conservative Senate Leader Larry Smith. (Graham Hughes/Canadian Press)

With only seven sitting weeks left before the summer recess, the pressure is on the Liberal government to pass bills before an expected fall election.

If the UNDRIP bill — which could have wide-ranging effects on Canadian law if it's fully implemented — doesn't pass by the end of June, it will die on the order paper. That would mean new legislation would have to be introduced in the next Parliament to implement UNDRIP.

While there is a sense of urgency given the constrained parliamentary timelines, the Aboriginal Peoples committee is already in the midst of two other "pre-studies" of government legislation that soon will go before the Senate: Bill C-91, the Indigenous languages legislation, and Bill C-92, Indigenous child welfare reforms.

Since the Aboriginal Peoples committee will be busy with that work for the next several weeks — and since Parliament isn't sitting for the next two weeks — the committee's review of the UNDRIP bill can't happen until sometime in May.

Complicating matters, the legislation is actually a private member's bill first introduced by NDP MP Romeo Saganash, who was also part of an international team that helped craft the declaration more than a decade ago. The government's representative in the upper house, Peter Harder, has fewer tools at his disposal to ensure a non-government bill is passed.

While the Liberals promised to implement UNDRIP in the last election campaign, then-justice minister Jody Wilson-Raybould announced in 2017 the government would simply back Saganash's bill rather than introduce separate government legislation.

But Wilson-Raybould herself has said de-colonizing Canadian law would require more than UNDRIP's adoption.

"As much as I would tomorrow like to cast into the fire of history the Indian Act so that Nations can be reborn in its ashes, this is not a practical option," she said in a speech to the AFN general assembly in 2016.

"Simplistic approaches such as adopting the United Nations declaration as being Canadian law are unworkable and, respectfully, a political distraction to undertaking the hard work actually required to implement it back home in communities."