The Royal British Legion has said it is opposed to moves to fly the union flag at Belfast City Hall's cenotaph every day of the year.
In a statement, the legion said its Garden of Remembrance was "sacrosanct" and it did not want it politicised.
The legion was responding to a DUP proposal to fly the flag at the cenotaph daily.
The submission by the legion will be included in a crunch equality impact report on the controversial flag issue due to be brought before a council committee tomorrow.
The proposal to erect the Union flag over the cenotaph permanently was introduced by the DUP following a vote last year to limit the number of days it could fly over the City Hall.
But with the full council set to reject the DUP motion, concerns have been raised that tensions within the City Hall could be raised once more over the contentious issue of symbols.
The decision by the council in December not to fly the Union flag from City Hall all year round led to street protests which blocked roads and caused massive disruption.
The spiralling violence cost millions of pounds in policing and lost trade to businesses, and prompted scores of arrests.
The cenotaph proposal, introduced by DUP councillor Lee Reynolds in December, is supported by unionists.
An equality screening was carried out on the issue and is due to be presented to the council's policy and resources committee tomorrow.
But a council source told the Belfast Telegraph: "The Royal British Legion aren't in favour of it flying."
"They have made a submission to the consultation – and were not in favour."
Another council source said: "The British Legion didn't want to be involved in it (the motion) and wanted it to be left the way things were – no change."
It is one of a number of submissions contained in the report. It is understood the advice is that there would be equality issues if the flag flew daily a the cenotaph.
The proposal is set to be rejected by Sinn Fein, Alliance and SDLP councillors due to "equality issues" in the report.
At a meeting of a diversity sub group on Tuesday, Alliance members indicated they were not going to support the motion.
The DUP has said it is not commenting publicly on the matter at this stage.
A unionist source, however, said they have been left "frustrated" as they were led to believe Alliance would have backed the motion.
"We are frustrated the Alliance Party has gone back on its word and that a possible path out of this situation has been significantly disrupted," the source said.
The matter will be officially discussed on Friday during the policy and resources committee.
Any decision will have to be ratified by a full council, which is due to meet on May 7.