Ghislain Picard, chief of the Assembly of First Nations of Quebec and Labrador, says First Nations have the right to determine their own future and aren't bound to the result of another referendum vote.
It's useless to consider Quebec sovereignty while there's still uncertainty about the place of aboriginal peoples, Picard said.
"We have the right to self-determination and this right is not negotiable," Picard said in a statement.
If the Parti Quebecois succeeds in getting a majority in the April 7 vote and works toward calling another referendum, Picard says First Nations will take steps to protect the interests of their members.
"Let us be even more clear: Quebec can decide what it wants in terms of its culture, its identity and its development, but it cannot claim sovereignty over a territory which is still, fundamentally, First Nation."
Similar concerns were raised in the lead up to the last referendum in 1995.
In that year, Quebec's Cree and Inuit both held referendums of their own and voted overwhelmingly against Quebec becoming independent.
Sovereignty became a major focus of the current campaign after media baron Pierre Karl Peladeau joined the Parti Quebecois last Sunday, when he raised his fist and declared he wanted to help make Quebec a country.
But PQ Leader Pauline Marois has moved away from the issue in recent days.
A new poll released Saturday suggests Peladeau's entry into the campaign, and the heightened focus on sovereignty, has favoured the Liberals more than the PQ.
On Saturday, Marois focused on the PQ's plan to address homelessness, while continuing to attack Liberal Leader Philippe Couillard for his approach to getting Quebec's distinctiveness recognized by the rest of Canada.
She even suggested Couillard call a referendum of his own on his constitutional plans.
For his part, Couillard appeared to back away from an earlier statement that as premier he would push federal, provincial and territorial officials to take Quebec's unique status into account in any constitutional talks.
Couillard said Saturday his priority in any relations with the rest of Canada would be the economy.
Saturday's Leger Marketing poll for Montreal's Le Devoir newspaper found the PQ and Liberals tied with 37 per cent of the vote, with Francois Legault's Coalition dropping to 14 per cent.
The poll suggests the PQ retains a lead over the Liberals amongst key francophone voters.
The poll also said 59 per cent of respondents would vote no in a referendum and 69 per cent want less talk of it during the campaign.
The online survey of 1,205 people between March and 13 has a margin of error of plus or minus 2.8 per cent, 19 times out of 20.
- with files from Julien Arsenault in Sept-Iles and Martin Ouellet in Boucherville
Follow @BenShingler and @JulienArsenault on Twitter
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