The government tells CBC News that 84 First Nations bands have until Wednesday to post their audited financial statements for the last fiscal year, including the salaries and expenses of their chiefs and councillors.
Under the First Nations Financial Transparency Act, First Nations had 120 days after the first quarter to comply with the new rules. In August, the government gave those holding out another 120 days to meet the new requirements.
First Nations from Treaties 4, 6 and 7 say the federal government is "threatening to withhold funding for non-essential services on Nov. 26" and that if they still don't comply after that, "funding for essential services will cease on Dec. 12."
"This tactic is designed to force local compliance to an unjust law by denying families access to essential programs and services," the Treaty First Nations in Alberta, Saskatchewan and Manitoba said in a written statement on Tuesday.
The office of Aboriginal Affairs Minister Bernard Valcourt said bands who had not complied by August were sent "several formal reminders."
"If there is no resolution, for bands that are refusing to comply with the law, the government will take action... which could include withholding of funding," Valcourt's office said in an email.
"This law was put in place to ensure that First Nation band members have access to the information they require and deserve about basic financial management practices of their chief and council, and to empower them to ensure band revenues are being used for their benefit."