Acknowledging that it was aware of the planned march – which has been widely publicised on the internet and in posters around Belfast – the commission said that it was powerless to ban a parade if the organisers did not ask it for permission to march.

Unlike Sinn Fein, which has asked the Parades Commission for permission to hold a protest march just before the homecoming parade, splinter republican group éirígí has said that it will not be asking the commission for permission to march.

Last night the éirígí plan – which would see protestors bussed in from Dublin, Armagh, Fermanagh and south Londonderry – was denounced as a "recipe for disaster" on a day when soldiers' families will be coming to welcome them home from Afghanistan and Iraq.

Promoting the protest, éirígí said it would "oppose" the homecoming parade and added: "Give the Royal Irish Regiment the only reception it deserves – a hostile one."

A spokesman for the Parades Commission confirmed that it had not been notified of the parade and said that there was nothing it could do to prevent a parade taking place if it had not been asked to adjudicate.

He did stress that if it does not approve a parade, it would then be illegal.

And, warned that anyone breaking the law would be "fully investigated".

He said: "The parade and any associated protests will be policed in an appropriate and proportionate way to ensure public safety, minimum disruption and an early return to normality.

"Any peaceful and lawful protest will be facilitated, however anyone in breach of the law will be fully investigated."

UUP Assemblyman Basil McCrea said that the rule of law should apply to everyone in society – including dissident republicans.

"Whatever we might think of the Parades Commission – and there are certainly good grounds for criticising its approach to the parading issue – there is a legal obligation on parade organisers to notify the commission of a parade," he said.

"The refusal of dissident republican groups to do so requires a firm response from the police and the commission.

"It is a matter of profound regret that Sinn Fein and the dissident republicans are attempting to politicise the homecoming parade.

"As the Bishop of Lichfield stated at the parade for the Royal Irish last week in their garrison town of Shrewsbury, that the conduct of the Royal Irish in Afghanistan modelled 'what it is like for Protestants and Catholics to work together'."

Another Policing Board member, DUP MLA Ian Paisley Jnr, said that it was outrageous that the organisers of a parade could avoid any chance of it being banned by simply not asking the Parades Commission for permission to march: "We have a pious Parades Commission blinding itself to the reality that there will be a serious protest and they are doing nothing about it.