The PSNI chief constable, Mr Hugh Orde, yesterday called for a review of parades legislation in a bid to bring supporters at flashpoint marches into line.
Mr Orde told the Northern Ireland Policing Board that the law on parade followers needed clarifying before the next marching season.
"Currently it seems to me, and I am not a lawyer, that the law excludes followers from the determination, thus limiting what the commission can do. We are not comfortable with any situation that can lead to misunderstanding and ambiguity."
The police came under fierce criticism when they escorted 250 supporters past angry protesters in the Ardoyne area of north Belfast on July 12th.
Nationalists accused the police of overturning the Parades Commission ruling, which ruled that only lodge members and marshals could take part on the return leg of the parade.
It was revealed at yesterday's Policing Board meeting that police hope to identify at least 21 people involved in rioting which led to 25 police officers and six soldiers being injured.
Mr Orde said, while the marching season had been relatively peaceful, the cost of policing this year's parades had run into millions of pounds. The deployment of tactical support units in Belfast alone had cost £1 million.
"I don't think the time can be far off when everyone, the police service, those who want to march, those who wish to protest and other key stakeholders in the community, recognise that this level of commitment is simply not sustainable."
Ulster Unionist board member Mr Sam Foster, referring to a situation where a number of soldiers were attacked in Ardoyne, asked if the PSNI was short of personnel on the day.
He called for assurances that the security forces would not be subjected to such levels of danger and humiliation in the future.
Mr Orde said members of the Parachute Regiment had shown incredible restraint when confronted by a crowd on July 12th.
He denied the problem was due to lack of resources. "It was a question of deploying from an area where there was no trouble to an area where there was trouble."