A Causeway Coast and Glens representative said her party warned of a financial 'crisis' at the council five years ago.
Sinn Fein councillor Leanne Peacock, who last week held a series of meetings with senior council officials, said current fears over cash problems at the local government body was no surprise.
Cllr Peacock also backed calls for Causeway Coast and Glens Council to undergo an independent, forensic audit.
She said: "The Sinn Féin council group have had a number of meetings recently with senior Council officials to express our concern over the ongoing financial crisis within the Causeway Coast and Glens council.
"Our priority at all of these meetings has been to explore outcomes and options that will offer the best possible protections to the ratepayers of the area.
"Protecting ratepayers and services has been our priority in each of the first five years of the Councils' existence when it has come to setting the rates.
"If other councillors had listened to Sinn Féin throughout this five year period then we would not be in the current mess and ratepayers would now not have to carry the burden for the mistakes of others.
"Instead other parties have buried their heads in the sand and pushed through zero 0% rates while refusing cost-saving proposals and efficiencies.
"All of this has been unsustainable and contributed to the situation in which we now find ourselves."
"The Council must learn from the situation it finds itself in.
"To that end Sinn Féin have consistently supported proposals for a forensic audit of the Council by an independent financial examiner and wish to see this process started at the earliest opportunity. We believe this is needed urgently in the interest of transparency and good governance."
Cllr Peacock added: "The Sinn Féin council team will continue the process of working through budgets, savings and income generations proposals and efficiencies to ensure that we can minimise the impact to ratepayers.
"This remains a work in progress and all of our elected representatives are engaged and committed to these processes which will continue over the coming weeks."
The local representative's comments come after a number of SDLP councillors alerted the Northern Ireland Audit Office of "serious concerns" for the financial viability of the council.
Cllrs Margaret Anne McKillop, Orla Beattie, Stephanie Quigley, Angela Mulholland, Ashleen Schenning, Helena Dallat O’Driscoll met officials from the Audit Office to record their concerns earlier this month.
It was after leaked minutes of a high-level senior officers' meeting of Causeway Coast and Glens Council held just before Christmas highlighted the perilous condition of the council's finances, and said that a rates hike of 15% would be needed this year.
"Last week the council told the County Derry Post: "A Finance Committee meeting was held on 16th January where elected members were updated on Council's current financial position, including an initial position regarding the rates estimates.
"These discussions are ongoing and the rates will be decided next month following Council approval."
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