Restrictions on an Orange Order march through a north Belfast flashpoint are absurd, the Protestant religious organisation's leader said.
The authority which rules on parades has barred the return of three Orange lodges through nationalist Ardoyne.
The pro-union Orange Order's Grand Master Edward Stevenson called on Northern Ireland Secretary Theresa Villiers to scrap the Parades Commission.
"The absurdity of preventing three Orange Lodges in Ligoniel from partaking in a dignified parade on their return from the Twelfth celebrations, while rewarding those who engage in violence and go out of their way to be offended by our traditions, has surely sounded the death knell for this charade of a commission," he said.
He told Orangemen at a flagship demonstration in Londonderry that republicans were engaged in a cultural war to erode all symbols of Britishness in Northern Ireland. It followed Belfast City Council's decision last year to restrict the flying of the Union Flag from the City Hall to designated days.
But the Co Tyrone farmer reserved his fiercest criticism for the Parades Commission, long a bete noire of the Orange Order.
"Recent days have also demonstrated the increasing incompetence of the Parades Commission as it continues on its relentless crusade to denigrate Orangeism and the values we hold dear," he alleged of the independent body, made up of figures appointed by the Government and led by community work veteran Peter Osborne.
Mr Stevenson added: "I call on the Secretary of State to immediately cease offering this unelected quango life support; and finally put it out of its misery - for the good of all in Northern Ireland."
Orangemen and nationalist residents in Ardoyne held talks before today's parade - the first time such formal dialogue has taken place.
The Parades Commission's decision to stop Orangemen marching through Ardoyne on their return from their Belfast gathering was taken following years of serious violence surrounding the march.
It met with condemnation from some unionists, with North Belfast DUP MP Nigel Dodds forced to leave the Commons over his language in the House, but was welcomed by nationalists like Sinn Fein.
Mr Stevenson was joined by the leaders of the Orange Order in Scotland and England as he told crowds in Londonderry that loyalists faced an almost daily onslaught on their British culture and heritage.
"Not content having subjected this province to terror and mayhem through a murderous campaign, and trying their best to rewrite history in an attempt to justify their vile actions, republicans are now engaging in a cultural war to erode all symbols of Britishness from this part of the United Kingdom," he said.
"The shameful decision to strip down the Union Flag from Belfast City Hall, following on from the outrageous naming of a children's play park in Newry after an IRA terrorist, are just some examples of the so-called 'shared future' envisaged by Sinn Fein.
"Such is their disdain for loyal order parades, we even have the disgraceful spectacle of the current Culture Minister at Stormont (Caral Ni Chuilin) - supposed to represent all the people of Northern Ireland - openly protesting against our very presence on the streets of our capital city.
"Surely not only is this a clear breach of the ministerial code, but I would remind Mrs Ni Chuilin that Orangeism is an integral component of the cultural fabric of the Protestant/pro-union community. We are not going to go away."
He expressed opposition to the proposed construction of a conflict resolution centre at the former Maze prison which housed paramilitaries near Belfast.
"We will simply not countenance the very real prospect of a terrorist shrine manifesting itself at the very site where those who inflicted nothing but anguish and sorrow upon the law-abiding majority were quite rightly incarcerated for their horrific crimes," he said.
"I want to make clear that the Orange institution is not being party political on this emotive and sensitive issue.
"We do not believe we are 'nutters' but rather are merely expressing the legitimate viewpoint of those most directly affected by our troubled past.
"The real victims deserve to be heard and we will do our utmost to ensure their concerns are listened to and acknowledged.
SDLP MLA Conall McDevitt said he was disappointed with the Order's words.
"We have heard the language of war by another means, of active conflict with and disregard for lawfully constituted institutions from the leaders of the Loyal Orders today," he said.
"The question those making these speeches must ask is whether they accept that a shared society will involve compromise by all and that the Good Friday Agreement, its institutions, safeguards and principles is and will remain the only show in town."