The Parades Commission has been urged to take into account bands' "compliance with the law" ahead of any Twelfth processions taking place this year.
The call comes as speculation grows that some loyalist bands which have taken part in illegal Northern Ireland Protocol protest parades may also seek to participate in the main Twelfth celebrations.
In recent weeks a large number of un-notified loyalist protest parades have been held in different locations across the north.
Unionists are angry at the protocol and how the Bobby Storey funeral was handled.
Concerns have also been raised about claims of two-tier policing.
During recent parades band members have been masked and have not worn uniforms while taking part in protests.
Identifying markings on equipment, including side drums, have also been covered up.
Under current regulations all public processions must be notified to the Parades Commission, which has the power to ban them or impose restrictions.
Many of the recent parades have not been notified, with the majority organised at short notice and at a local level.
Last year's public Twelfth celebrations were cancelled due to the current pandemic and while no final decision on whether this year's event will go ahead has been made, Orange Order grand secretary Rev Mervyn Gibson said last month said the “signs were looking good” for a return to normal this year.
The senior Orangeman said yesterday on BBC Radio Ulster he can "see the protests to the protocol increasing, I can honestly as Covid restrictions are lifted and more people go out I think people join those protests."
It recently emerged that 14 loyalists have been asked by letter to attend PSNI interviews voluntarily after a number of notified and un-notified processions in the Markethill area of Co Armagh.
The suspects have been told that "failure to make contact with police to make a suitable date for interview, within 14 days of receipt of this letter will result in you being reported to the Public Prosecution Service for the offences listed above".
SDLP Policing Board member Dolores Kelly said she would "urge everyone to abide both by the letter and the spirit of the regulations.
"The Parades Commission will be expected to continue to adjudicate with impartiality," she said.
"They will have to take into account the behaviour of any band and the members' compliance with the law.
"Poor behaviour by others should not be the bar we set for ourselves."
Asked last night if any more letters have been delivered in other areas a spokesman for the PSNI said: "Where Police suspect a breach under the Public Processions (Northern Ireland) Act 1998 and/or Public Health Regulations (NI) 2021 have occurred, we have an obligation to investigate and will do so.
"The distribution of letters forms part of our investigative process."
A spokesman for the Parades Commission said "unnotified parades are a matter for the PSNI to investigate".
"The commission does not have knowledge of whether anyone who participated in such a parade has subsequently submitted a notification for a parade.”
More protest parades are planned for Ballyclare and Kells in Co Antrim later this week.
